When source files are moved behind a running instance of DrJava and a 'find all' is used to search all documents, a dialog pops up saying that the files can't be found. If you select 'Yes' to find a file, the file chooser pops up and a NullPointerException is thrown.
Was found while working on Feature Request 2977070 - 'Option to abort failing global...', but is not a result of those changes. This bug is present in the latest beta, 20100415-r5220.
The stack trace is extremely short and I couldn't figure out what was going on; it is attached.
Note: this error does not interrupt the process of choosing a file. It's just annoying.