When annotations were added to the platform in Java SE 5.0, early builds used a different representation of annotations in the class file than the final format. Support for this intermediate format has now been removed. Reading an annotation from a class file using the intermediate format which differs from the final format yields an exception similar to:

`java.lang.reflect.GenericSignatureFormatError: Signature Parse error: Expected Field Type Signature`

Recompiling the sources or otherwise regenerating the class file to conform to the proper format will resolve the issue.