Only one content examiner implementation can be registered

I am facing this strange error when checking in a component. I cannot check in any of the files. this is with RTC 2.0

The full stack is:

Failed to upload file .....

java.lang.IllegalStateException: Only one content examiner implementation can be registered
at com.ibm.team.filesystem.client.internal.SharingManager.getContentExaminer(Unknown Source)
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.init(Unknown Source)
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.getPredecessorHintHash(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession.internalDoStoreContent(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession$3.run(Unknown Source)
at com.ibm.team.repository.client.util.ThreadPool$PoolJob.run(Unknown Source)



Anybody has seen this? what can I do?
Thanks,
Alain