Got a couple of complaints from users unable to add documents to the Briefcases shared with them. I tested it myself and got the same error.
I basically shared the Briefcase (with manager permissions) with another user and went to that user's account and tried to put a document on the briefcase and got an error "A file cannot be copied to a shared folder." I tried the same process with Admin permissions and still no dice.
I'm wondering if anybody else has seen this issue