Mark,
Just want to make sure that you are aware that the Invocation exception is happening now and the folder directory behaves weird again.
My directory is Root/TigerShark/IdentificationData/
When I click on the TigerShark folder, it should show IdentificationData folder but it displays TigerShark again.
When I click on navigation TigerShark tab link on top, the IdentificationData folder icon disappears and it becomes file.