title: Java: Unresolved compilation problem
body: <p>What are the possible causes of a "java.lang.Error: Unresolved compilation problem"?</p>
  
  <p>Additional information: </p>
  
  <p>I have seen this after copying a set of updated JAR files from a build on top of the existing JARs and restarting the application. The JARs are built using a Maven build process.</p>
  
  <p>I would expect to see LinkageErrors or ClassNotFound errors if interfaces changed. The above error hints at some lower level problem.</p>
  
  <p>A clean rebuild and redeployment fixed the problem. Could this error indicate a corrupted JAR?</p>