When I try to exit PSA SE 3.0 it brings up a small status window stating "Completing Pending Operations..." 20%. It never gets further than 20% and will not close the application. The application is not hung for I can click "Return to application" and it will promptly do so.
I have also seen this window but it disappeared after the pending operation was completed. It generally occurs when the application is busy generating previews/thumbnails of the photos or any other pending operation. This window should disappear after sometime.Does this happen in your case, or it remains there forever?
Earlier in the day I did up load 500+ images. That evening I let the application sit in the pending operation mode for at least an hour. A few days later my DH ended up doing an 'end task' on the application so he can run another application. I now am able to open and exit successfully but I haven't up loaded additional images. When I do and if I get that message again I will let the application work at it for a while longer.