When I exit a file in our PW managed workspace, I often get this a message box carrying this message. The dialog title is Bentley InRoads V8i (SELECTseries 4) so I am attributing this error to InRoads and not Project Wise. If that is wrong, feel free to move this post to that forum.
Could be. I was working on an AECOM datasource as well.
I would cross post this to the ProjectWise forum - and possibly have a chat with the AECOM PWise administrator. (I am not a PWise person.)