title: Automatic Extension Update: Unknown Archive type
body: <p>I have created a new version of my Joomla extension.</p>
  
  <p>Manual upgrade via zip file or the directory works fine.</p>
  
  <p>But the automatic upgrade (which used to work fine before), now gives an error 500 and the following error messages: "Unknown Archive type", "*Update path does not exist" and "Installation unexpectedly terminated: Update path does not exist".</p>
  
  <p>I have no idea why those messages appear. </p>
  
  <p>The update.xml references the correct zip files. Downloading it manually works just fine.</p>
  
  <p>Joomla(/php/apache) has all rights on the folder containing the joomla installation.
  After trying the automatic update, the tmp folder contains the downloaded zip archive with the latest extension version, interestingly without the .zip extension. Is the Joomla downloader not correctly naming the file and then failing upon finding that the file doesn't have a .zip extension?`Or what could it be?</p>
  
  <p>Would be very thankful for any ideas...</p>
  
  <p><strong>Edit:</strong> My project is hosted on github, and github seems to automatically create a subfolder in the downloaded zip archive, named -.zip.</p>
  
  <p>I'm using a link to the tagged github zip directly in my update.xml</p>
  
  <p>I'm not sure if github always added this folder in the zip file, back when it still worked for me...</p>
  
  <p>Might the Joomla problem have to do with the zip file containng such a folder, and not directly the extension stuff at root level? If so, anybody know if/how I can change github to not create that subfolder?</p>