Exception in thread "Java indexing" java.lang.IllegalArgumentException: Document path **path unknown** must be relative to **path unknown**
	at org.eclipse.jdt.internal.core.index.Index.containerRelativePath(Index.java:107)
	at org.eclipse.jdt.internal.core.search.indexing.InternalSearchDocument.getContainerRelativePath(InternalSearchDocument.java:32)
	at org.eclipse.jdt.internal.core.search.indexing.InternalSearchDocument.removeAllIndexEntries(InternalSearchDocument.java:40)
	at org.eclipse.jdt.core.search.SearchDocument.removeAllIndexEntries(SearchDocument.java:128)
	at org.eclipse.jdt.internal.core.search.JavaSearchParticipant.indexDocument(JavaSearchParticipant.java:68)
	at org.eclipse.jst.jsp.core.internal.java.search.JSPSearchParticipant.indexDocument(JSPSearchParticipant.java:72)
	at org.eclipse.jdt.internal.core.search.indexing.IndexManager.indexDocument(IndexManager.java:354)
	at org.eclipse.jdt.internal.core.search.indexing.IndexManager$1.execute(IndexManager.java:692)
	at org.eclipse.jdt.internal.core.search.processing.JobManager.run(JobManager.java:394)
	at java.lang.Thread.run(Thread.java:810)