title: GWT AbstractMethodError(Linker.link): possible factors?
body: <p>First of all, I am sorry for asking such a general question without a lot of details.
  If you feel that this cannot be answered, feel free to ask for other details, or just go about your day please. Newbs know when they are asking annoying general questions and don't need to be told that.</p>
  
  <p>My situation is i have been given a GWT project to take ownership on and I don't have access to the authors.</p>
  
  <p>When starting the project in development (hosted) mode I get the following error:</p>
  
  <pre><code>Linking module 'com.mymodule'
          Invoking Linker RPC policy file manifest
             [ERROR] Failed to link
  java.lang.AbstractMethodError:com.google.gwt.core.ext.Linker.link(Lcom/google/gwt/core/ext/TreeLogger;Lcom/google/gwt/core/ext/LinkerContext;Lcom/google/gwt/core/ext/linker/ArtifactSet;)Lcom/google/gwt/core/ext/linker/ArtifactSet;
  at com.google.gwt.core.ext.linker.impl.StandardLinkerContext.invokeLink(StandardLinkerContext.java:408)
  at com.google.gwt.dev.DevModeBase.link(DevModeBase.java:947)
  at com.google.gwt.dev.DevMode.doSlowStartup(DevMode.java:374)
  at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1057)
  at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:783)
  at com.google.gwt.dev.DevMode.main(DevMode.java:275)
  </code></pre>
  
  <p>Uninformative, to say the least. I have been trying to figure this out but to no avail.
  What are the possible causes to this error and how do I go about determining them?</p>
  
  <p>Thank you!!</p>