Adobe add-on automatic file checking
When you are using the PageProof Adobe add-on to create proofs directly from Adobe apps and work through the proof comments, the Adobe file ID is checked against the proof ID. This helps to ensure you’re working on the correct file.
What does the warning icon mean?
If a warning icon is seen, the Adobe document (or project) ID does not match to the proof, meaning it was not the file used to create the proof.