Have you tried to force quite Indesign? I had issues with this a few versions ago. Ended up turning off background export for difficult files. Haven't had in a long while. What version are you using?
Thanks for responding! Unfortunately I already tried that a few times. It just keeps saying that I can't quit InDesign. I'm using the latest version (CC 2017).
I am having the same problem, did you find a solution to this?
That has happened to me the day before my final was due. It is still saying it's canceling and will not let me quit. Did you find a solution to this?
If I get your query InDesign background task is running continuously for days which is not allowing InDesign to shut down?
In order to assist further on this I would need some details like
Operating system (Exact version of MAC or Windows).
Version of InDesign
1) Try resetting your InDesign Preferences: Close and relaunch InDesign, and IMMEDIATELY hold down Ctrl + Alt + Shift (Windows) or Cmd + Ctrl + Opt + Shift (Mac), and respond in the affirmative to the dialog asking if you really want to replace the preferences. you must be extremely fast on the keyboard (if you don’t see the confirmation prompt, you were too slow)
You may have to do it a couple of times before you get the hang of it!
2) If it's still crashing try this: uninstall InDesign, using the drop-down in the Creative Cloud app (the cog icon), then run Adobe Cleaner before reinstalling InDesign.
3) Untick in inDesign Preferences undertake GPU Tab, tGPU Performance.