It means what it says.
Can you be a bit more specific where this text appears and at what occasion?
I have a FM12 file in a folder and when I try to open the file I get the message.
Any chance this is a FileMaker database that also had external container field folders and you forgot to include them when maybe you moved the FM12 file?
No, I've been using it from that same folder for 3-4 days.
It is backed up though.
Not to sound like a smart alec, but it might pay off to check the mothership once in a while:
(yes, that's the entire URL)
FileMaker, Inc. is aware of this issue with the FileMaker products listed?....Hmmm.