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Mylyn User Guide, Mylyn Home, Log in to edit

For instructions on downloading installing and configuring Mylyn, see the Mylyn User Guide. For instructions on developing and contributing to Mylyn, see the Mylyn Contributor Reference.



What versions of Eclipse are supported?

See the download page.


What version of Java is required?

Mylyn needs the Java 5 virtual machine.





export JAVA_HOME="(location of JDK1.5 root)"
export PATH=$JAVA_HOME/bin:$PATH



What version of Mylyn is distributed with the Eclipse downloads?


  • Eclipse Classic: no Mylyn redistribution, install manually

My tasks or queries disappeared, what do I do?

This happens if Mylyn failed to install. First ensure that you have a correct install by following the instructions in the next section. After that, if you still do not see your tasks use the Task List view menu -> Restore Tasks From History... command (also available via File -> Import -> Task List.

Installation Troubleshooting

Java Persistence API Tools error when updating the JEE Eclipse Package


Update failures

On Eclipse versions earlier than 3.3 (final) use only the "Search for new features.." option when updating Mylyn. If you use "Search for updates..." the Update Manager will allow a partial install that can cause Mylyn to fail to start, and you will need to run update again. See the feature configuration problem section below for details. If you encounter this problemm consider voting for Platform bug 132450.

Startup exceptions

If you see startup errors or warnings such as BundleException or timeout messages restart Eclipse with the -clean flag either on the command line, in your shortcut link, or by temporarily it into the eclipse/eclipse.ini file. If that does not resolve the problem please file a bug.

Incompatible VM (e.g. JDK 1.4)

If you are using the wrong VM, you'll see errors like the following in your log file.

   Root exception: java.lang.UnsupportedClassVersionError:

See Configure Java to fix this problem.

Incompatible version of Eclipse


   java.lang.NoSuchMethodError: org.eclipse.ui.internal.dialogs.FilteredTree.getFilterControl()
   The activator for bundle is invalid

Mylyn feature configuration problem

If the above do not address the issue, the easiest thing to do is uninstall any old versions and update to the latest Mylyn. Your tasks won't be lost, because by default they are stored in the <workspace>/.metadata/.mylyn folder which will be read next time Mylyn starts correctly.

  • First, uninstall the old version of Mylyn using Help -> Software Updates -> Manage Configuration.
  • Allow Eclipse to restart after the last is disabled.
  • Uninstall all the disabled features using the popup menu.

If you don't uninstall, the the Update Manager will think that you have the latest and tell you that there are no updates.






I've installed Mylyn ; why can't I see anything different?

The two most likely possibilities are:

  1. You don't have any Mylyn views open. Select Window -> Show View -> Other, then select Mylyn and you should see the available Mylyn Views.
  2. If you still don't see anything, then perhaps you aren't using the JDK1.5 VM (or later). See configuring Java.

What does the error "Network connection problems encountered during search" mean?


What does the "Update manager failure" message mean?


If you are trying to update the JIRA connector you can also try de-selecting that feature in case the update site is not accessible. Using Search for new features to install.. when installing can help to avoid this problem. If that does not work see the feature configuration troubleshooting below.

What does "Could not create Browser page: No more handles (java.lang.UnsatisfiedLinkError: ...)" mean?

It probably means that you are running Linux and don't have Eclipse and a Web browser configured to work together. See [installing a browser on Linux].

When downloading, why do I get a warning that the feature was unsigned?

Signing plugins requires extra administrative details with which most plug-ins seek to avoid.

N.B.: Security issues with features should not be underestimated. Eclipse allows users to download new functionality from remote servers. A rogue plug-in can act as a perfect Trojan horse. It can look innocent enough and provide useful function while spawning threads in the background with full access to the local file system and the Internet (if connected). Beware of installing features from update sites you do not trust.

What does "Root exception: java.lang.UnsupportedClassVersionError: org/eclipse/mylar/tasklist/MylarTasklistPlugin (Unsupported major.minor version 49.0)" mean?


Why am I getting messages in my <workspace>/.metadata/.log or my Mylyn view that say things like "java.lang.NoSuchMethodError: org.eclipse.ui.internal.dialogs.FilteredTree.getFilterControl()" and "The activator for bundle is invalid"?

This probably means that your Mylyn download version didn't match your Eclipse download version. Note that the download site has different downloads for Eclipse 3.1 and Eclipse 3.2.


What does "Could not create Bugzilla editor input" and " SAX2 driver class org.apache.xerces.parsers.SAXParser not found" mean?



I've just updated to Mylyn 2.0 and I don't see any tasks in my Task List


Configuration Troubleshooting


Turn off or increase the number of editors to leave open using Preferences -> General -> Editors -> Number of opened editors before closing. Since Mylyn will manage the open editors with task activation, this number can be set higher or you can disable automatic closing entirely.

Do I need the Outline View when running Mylyn?


What does the message "content assist proposals no longer appear" mean?

This usually happens when uninstalling when using Eclipse 3.2. Make sure that the "Java Completions" and "Java Types" proposal categories are included in the default proposals via: Preferences -> Java -> Editor -> Content Assist -> Advanced -> Restore Defaults. Also see: content assist troubleshooting. This bug has been fixed in Eclipse 3.2.1.

Why do I get errors like "HTTP Response Code 407" or "Proxy Authentication Error" when accessing repositories through a proxy server?

It is likely that you need to configure these proxy server settings. Select Window -> Preferences -> Install/Update, and update the section in the "Proxy settings" section of the form.

I can't use Ctrl+Alt+Shift+Arrow Up for Mark as Landmark. What do I do?

This is usually a Linux/GNOME problem, where the Gnome keyboard shortcuts are interfering with the Eclipse shortcuts. Go to the Keyboard shortcuts (which might be something like Desktop -> Control Centre -> Keyboard Shortcuts or System -> Preferences -> Keyboard Shortcuts) and disable both of these shortcuts:

  • Move one workspace up
  • Move one workspace down

See also: keyboard mappings on Linux.

How do I turn on spell checking?

See spell checking.

Uninstall troubleshooting

When uninstalling in Eclipse Mylyn via the Help -> Software Updates -> Manage Configuration dialog you will need to uninstall dependencies first (e.g. Bugzilla Connector, Subclipse integration) and then uninstall the core Mylyn features.


On Eclipse 3.1: you may need to reset the Java editor to be default for .java again via: Preferences -> General -> Editors -> File Associations


I am seeing java.lang.OutOfMemoryError: PermGen space errors, what's wrong?

If your Eclipse crashes, or you see the above error after installing Mylyn or other plug-ins, you have most likely hit the infamous MaxPermSize bug. This is not a Mylyn specific problem, but a general Eclipse problem that is often triggered on Eclipse 3.2 and later, if you have many plug-ins installed and are using a Sun JVM.


   -vmargs -XX:MaxPermSize=128M

Or to the eclipse/configuration/config.ini file:





What is Mylyn's performance profile?

Mylyn should have no noticeable effect on Eclipse's speed or memory usage, no matter how large your workspace is. You do not need to increase the amount of memory Eclipse runs with to use Mylyn. Any performance issue should be reported as a bug.

The current performance profile is:

  2. Task context models have negligible memory overhead.

If you are seeing performance problems, this is either a bug or caused by other performance problems in Eclipse. If you are performance problems we suggest increasing the amount of memory available to Eclipse. This is especially useful for very large Java project workspaces, on which the size of JDT's element cache will grow proportionally to the amount of available memory. The setting we recommend for launching workspaces with a couple hundred large projects is:

 -Xmx768M -XX:MaxPermSize=128M

Task List

Why won't the Archive category disappear?


  • Repository tasks that have incoming changes, such as comments. Remove these by reading them or marking them as "read" via the Mark -> Read pop-up menu.

The Archive category contains many irrelevant tasks, how do I clean it up?

If you created very broad queries you could end up with thousands of tasks in the Archive category. Other than clearing the workspace/.metadata/.mylyn/ and workspace/.metadata/.mylyn/offline folder (note that this will entirely reset your Task List) the easiest option is to:

  • Turn off Focus on Workweek in the Task List.
  • Turn off the Filter Archive Category option in the Task List view menu.
  • Delete all of the unneeded tasks from within the Archive category. Note that if the tasks are not matched by queries they will be deleted permanently and any local notes or scheduling information that you have added to them will be lost.

How does Mylyn count the active time for a task?




Does the Task List replace the Eclipse Tasks view?


What if I use multiple workspaces?

Mylyn's support for multiple workspaces is currently limited (see bug 130658 for a discussion) because the Task List is considered to be specific to the person, and not to the workspace. We recommend configuring your Eclipse workspace to use working sets instead of relying on multiple workspaces.

If using a single workspace is not possible you can do the following:

  • In Preferences -> Mylyn -> Task List set the Data Directory to be a shared location, and do this for both workspaces.
  • If you upgrade Eclipse or move your workspace and don't see your tasks, check the Data Directory setting.

How do I export my task and repository data?

Export via File > Export > Mylyn > Task Data

Why does Mylyn use the term "task"?

There are many work items that make up the developer's workday. Many issue trackers and project management tools refer to these as: bugs, defects, actions, tickets, stories, enhancements, and the list goes on. We refer to all such work items as "tasks" because the word tasks is short and commonly used in time management tools. Task Repository connectors can customize the presentation of tasks, for example, indicating which is a defect and which is an action item.

Why are closed tasks not greyed out on Linux?

If you are running Eclipse from KDE go to KControl -> GTK Styles and Fonts and select "Use another style" in the GTK Styles section (bug 206399).

Task Editor

When I submit a new bug to the priority isn't updated?'s Bugzilla repository forces all new bug reports to priority 3 (P3) regardless of what is selected in Mylyn. Eventually we will disable this field in the new bug editor for and provide a tooltip with explanation ( bug 204630 ).


If for example you aren't seeing the proper single quote chacters in the summary of [bug#197644], check that the encoding is set correctly for the repository in the asociated Task Repositories view (Properties > Additional Settings > Character Encoding). For set your charcter encoding to ISO-8859-1.

Task Repositories

What if I'm not using a Task Repository?



What if Mylyn doesn't support my task/bug/issue/ticket repository?




To create a task from any web-based repository:



Why were my repository credentials reset?


Why are my updated repository attributes not showing up?

Your server's repository attributes can change frequently, for example, there can be a new "milestone" or "version" added to the Bugzilla repository with each release. When the Preferences -> Mylyn -> Task List -> Synchronization setting is enabled, every 10th synchronization will update the attributes from the repository. If you do not have this setting enabled, your can force the update via the Update Attributes action on the task repositories' context menu in the Task Repositories view. Note that you will need to reopen a task editor to see the updated attributes. If you instead update via the button on the Attributes section of the Task Editor the attribute settings will be reloaded without needing to reopen.

Authentication Troubleshooting


  1. Enter the repository URL (i.e. and an optional label
  2. Credentials
    • Usually email address and password
    • Some sites, such as, use anonymous logon with password left blank.
  3. Http Authentication (optional)
  4. Proxy Server Configuration (optional)
    • By default Mylyn uses the Platform's Install/Update proxy settings. Uncheck this box if you wish to use an alternative proxy.
  5. Validate Settings
    • Press the validate button to test the settings
    • If you are seeing errors like "HTTP Response Code 407" or "Proxy Authentication Error" it is likely that you need to configure proxy settas as described above.

Certificate authentication

In order to use client certificates for authentication you need to create a Java keystore and import your existing certificate to it. This command will import your certificate from /tmp/certificate.pem and create a keystore in /path/to/.eclipsekeystore.

keytool -import -keystore /path/to/.eclipsekeystore -file /tmp/certificate.pem

See this page for links to the keytool documentation.

Add the path to the keystore to your eclipse.ini in your eclipse install directory:

If your keystore is protected by a password add that as well:

More instructions on this blog.

NTLM authentication




  • If your repository uses MS NTLM authentication and only standard http authentication is being passed to the repository this can result when the local hostname cannot be resolved. Ensure your machine's hostname is set correctly and resolves to a valid address.


Why are task hyperlinks not working?



Note that to view a hyperlink you must hold down the Ctrl key when hovering over the reference to the task. References to tasks are connector specific and the common reference is found on the top left of the task editor and other conventions tend to follow those used in the web UI (e.g. "bug 123" for Bugzilla, "ABC-123" for JIRA).


Bugzilla Connector

What versions are supported?

We recommend using the latest release of Bugzilla.

  • Bugzilla 2.18.6 is the lowest version of Bugzilla supported. If you are getting errors that indicate failure to update attributes this may be an indication that the Bugzilla server is not supported (< 2.18.6).

Why are queries failing?

  • If queries are not working correctly ensure that you have the right Bugzilla server version selected for the corresponding repository: Task Repositories (View) -> right+click the repository -> Properties. For supported versions see the download page. If the repository is still not functioning it may be due to authentication or connectivity problems. If that does not resolve the problem please post a message to the newsgroup or submit a bug.

Why do I see my old username?


Why do tasks fail to open?

  • If upon opening a bug, the Bugzilla tab only displays a warning "Could not download task data, possibly due to timeout or connectivity problem. Please check connection and try again.", ensure that your repository is returning XML data by pointing your browser to <your-repository-url>/show_bug.cgi?id=1&ctype=xml to show the contents of bug 1 in XML form. The Bugzilla client requires that bugs be accessible in XML form. If the repository doesn't support xml then it is likely that the repository is too old (Mylyn currently supports Bugzilla 2.18 and later).
  • If reports fail to load or reports fail to synchronize (task description remains italic), check the error log for a "File not found" error pointing to bugzilla.dtd or a "Failed to retrieve products from server" error message, these can result when
    • the urlbase parameter is not set on the bugzilla server
    • your urlbase parameter is incorrect, e.g. it contains index.cgi

    • Synchronize the task in the Task List
    • Reopen the task - new options should be available.

Why do tasks fail to submit?

  • Error upon submit: unable to make any match for name/email entered. If your bugzilla is configured for user names rather than full email address the QA Contact field will cause the submit to fail (bug# 166555). To resolve, select 'Local users enabled' option on the Repository Configuration page.
  • If tasks fail to submit with credentials error, but the repository validates fine, make sure that you've correctly setup your account's username and password and are not using the HTTP authentication fields instead.
  • If tasks fail to submit with credentials error, but the repository validates fine, make sure that you've correctly setup your bugzilla instance's cookie domain under the required settings. The cookie domain must lead with a dot.
  • If attachments are failing to submit and you see that after processing the attachment, the bugzilla bug shows a size of "bytes" (no numbers), your database may be dropping the packet sending the file. On MySQL, check the max_allowed_packet directive. You may see errors like: DBD::mysql::st execute failed: Got a packet bigger than 'max_allowed_packet' bytes [for Statement "INSERT INTO attach_data (id, thedata) VALUES (38, ?)"] at /path/to/bugzilla/attachment.cgi line 993. Also, check the maximum attachment size in Bugzilla Parameters -> Attachments.

What time zone is used in the task editor?


Known limitations

  • Version 1.0 of Mylyn presents an error message upon new comment submission to RedHat's public Bugzilla repository. The comment is in fact posted. This issue is resolved in Mylyn 2.0M2 and higher. (bug#183251)

JIRA Connector


 at org.tigris.jira.internal.core.service.soap.SoapJiraService.getProjectsNoSchemes(

What are the server requirements?

The JIRA SOAP/RPC services have to be running on the JIRA server:

  • Jira 3.3.3 or higher (3.7 or higher for attachment retrieval)
  • Jira RPC plugin 1.4.3 or higher

Latest information also available on the download page.

Related Resources:

Why can't I connect?

  • Similarly, if you get a "Processing instructions are not allowed within SOAP messages" message, ensure that SOAP/RPC services are on.
  • If you get a AuthenticationException and a query won't synchronize, use Task Repositories (view) -> Properties (on the repository) -> Validate Settings. This will clear the connection if it died.

Why do I get a "JIRA connector requires server 3.3.3 or later" message?

Version 2.0 of the Jira connector misinterprets version 3.10 as being lower than version 3.3.3. This is fixed in version 2.1 of the connector. Mylyn 2.1 is not compatible with Eclipse 3.2, but Eclipse 3.2/Mylyn 2.0 users can download a later version of the Jira connector from the weekly build download site; the latest Jira connector supports Mylyn 2.0 and Eclipse 3.2. If you get a NullPointerException from the update manager, make sure you've only searched the weekly download Extras site; don't search the 2.0 site at the same time.

Known limitations

  • blank but editable custom fields doesn't appear in the RSS data, and as result we can't show them for editing

How can I enable compression for SOAP messages?


  • Enable compression in your global JIRA configuration.

Reporting issues

Since JIRA can be heavily customized there is a chance that some particular customizations may not work, so if you can't connect to your proprietary repository it is a good idea to try the following public repositories to make sure you have working configuration:

If you can't get query results, you could try to call "Open with Browser" on query node in the Task List view and then save link "Current view: XML" and attach it to the bug report.

Even if query don't work you could try "Open Repository Task" from your JIRA repository node on the Task Repositories view and check if you can open JIRA task editor for that issue. Same for the Task search (Ctrl-H, Task Search)








In some cases unexpected redirects can be caused by a JIRA server accessed via Apache and mod_jk (using the AJP/1.3 Tomcat connector). Some server configurations may benefit from the 'proxyHost', 'proxyPort', 'scheme' and 'secure' settings on the AJP Connector in the Tomcat server configuration.

Please see bug 202834 for a more details.

Trac Connector

What are the server requirements?

The Trac connector offers two access methods:

XML-RPC (recommended)





  • Trac 0.9 or later


Recommended Trac version

Mylyn should work with any stable release Trac release that is version 0.9.x or 0.10.x (see below for known limitations). Mylyn works best when used with Trac's XML-RPC Plugin (see above) but we do not recommend a particular Trac version.

The Trac connector tests are run against these Trac versions:

  • Trac 0.10.4, XML-RPC Plugin rev. 1950
  • Trac 0.9.6

See bug 175211 for details about Trac 0.11 support.



Known limitations

  • Trac 0.10.1
  • Trac 0.10.3
  • Trac 0.11
    • Currently untested.
    • Known incompatibility with Trac XML-RPC Plugin See [2] for details.



Which URLs does Mylyn access in a Trac repository?




  • Authentication: /login
  • Querying: /query?format=tab...
  • Synchronizing ticket details: /ticket/...


Generic Web Repository Connector

Where can I find the web repository connector

It is available from the extensions update page. Please see

Why can't I connect using one of the existing templates?

The Web Repository Connector have a Preview option in Advanced Configuration section on the Query preferences. If you get an error or preview table does not show expected list of tasks you can use Query Pattern like (.+?)(\n) to see content of the retrieved page and compare it with the source of the web page for the same url loaded into the web browser.

If that does not help then you could use the wget tool (on Windows it available as a standalone command line tool and also included with Cygwin).

Run the following command:


If repository require basic http auth, you'll need to use --http-user=USER and --http-password=PASS options.


A popular mistake is an unmasked '?' that separates request parameters in the url). For example:



Known limitations

  • In Mylyn 1.0: if a web server responds by requesting a redirect to an absolute URL while fetching a resource, the connector falsely prepends "/" to the URL and the request will fail. The workaround is to use final url where redirect is pointing to (you can find it as describe above). See bug 167282 for details.

Task-Focused UI

What is the Task-Focused UI?

When you activate a task, Mylyn automatically maintains a task context by monitoring your interaction. The task context provides a predictable degree-of-interest weighting of the relevance of the elements and relations that you work with to the task-at-hand (as described in the Foundations of Software Engineering conference paper). The Task-Focuse UI is the mechanism by which Mylyn presents Mylyn the task-context model in order to reduce information overload and to automate the manaul management of UI elements like editors and change sets. Examples:

  • Filtering, decoration and expansion management in views
  • Automatic folding in editors
  • Ranking in content assist
  • Editor management
  • Perspective management
  • Change set management

Why do files disappear from Focused views when I close them?

By default Mylyn automatically manages the set of open files to match the task context, so that you don't have to. This ensures that the editor list (viewable via mechanisms like Ctrl+E) corresponds to what you in views like the Package Explorer when they are in Focused mode. When you close a file manually, you express that it is uninteresting, and as such it will be removed from the task context. It will also disappear from the corresponding automatically managed change sets for the same reason. This behavior can be turned off via Preferences -> Mylyn -> Context -> Manage open editors to match task context. However, it is highly recommended since Mylyn will prevent the number of editors from bloating by automatically closing editors for elements that have decayed in interest, and always keep the editors for interesting elements open.

Why did all my editor tabs disappear?


Mylyn actively manages your open editors with task context. It takes some getting used to, but enables switching between tasks when you are multitasking without cluttering your editor tabs. This editor management can be disabled via Window -> Preferences -> Mylyn -> Context. However, before disabling it consider reading the "Managing open editors..." section of Task-focused programming with Mylar.





Which Focused UI features can I turn off?

All of them. When no task is active neither are any of Mylyn's features. When working with task contexts Mylyn's Focused UI features are all optional and in general configurable. While many find it the key benefit of Mylyn, the entire Focused UI is optional and can be uninstalled via Help -> Software Updates -> Manage Configuration.

The following table summarizes how the key features can be toggled:

UI Mechanism Example/description Toggle using
Interest filtering Package Explorer Apply Mylyn button on view toolbar
Automatic toggling of filtering Package Explorer Preferences -> Mylar -> Context -> Toggle focused mode..
Active views Active Search and Hierarchy Only on if view is active

For additional configuration options see the Mylyn and General -> Appearance preference pages.

What happened to the Active Search and Active Hierarchy views?




Java Development

Content assist troubleshooting



Why do I see duplicate proposals?

Ensure that you have only the (Mylyn) proposals kinds enabled in Window -> Preferences -> Java -> Editor -> Content Assist -> Advanced, otherwise you will see duplicates.


Why do I get an error message when using content assist?






Why do interesting elements not show in the Project Explorer?

The Package Presentation -> Hierarchical mode is not supported on the Project Explorer view in Eclipse 3.2 through 3.3M3 and possibly later versions ( bug 161362). Use the view menu to set Package Presentation -> Flat as a work-around.

How do I stop declarations from showing in the Package Explorer?





Known limitations

  • Bug 106678: The Project Explorer's Hierarchical Java package presentation layout is not supported on Eclipse 3.3Mx, and interesting elements will be hidden if enabled. Work-around is to use the default Flat package presentation.

Team Support

Why does task change set not appear when I modify files?



  • You may be seeing the Synchronize view's refresh problem (bug 142395). Toggle from Incoming/Ougtoing to Incoming mode and back again to refresh the view.



Why am I missing elements when I retrieve someone else's context?


The work-around is to use the same project names across your team's workspaces. We recommend the following two approaches for standardizing on project names:

  • Use Team Project Sets: these are a very useful Eclipse facility that allows your entire team to check out numerous projects from version control by importing a single file. Create a project set via File -> Export -> Team Project Set, host this file somewhere accessible, then have others import vai File -> Import -> Team Project Set.
  • Have developers check out projects into their workspace without renaming them. The above is a shortcut for doing this. If alphabetical sort order in the Package Explorer is a problem, organize your projects via Project Explorer -> view menu -> Top Level Elements -> Working Sets.


How does Mylyn relate to IBM's Jazz?

