Logic Pro X - disappearing popup, screen flashes, can't quit!

I'm really hoping there is a simple workaround for this. Its driving me daft! I am using two monitors. If a device, such as an audio device or midi device or control surface etc is removed while I'm away from my MBP, or if for any reason at all that Logic decides to alert or notify me of something, I can see there has been a notification, and generally speaking, a popup alert if there is on. If I click on the notification, I generally see that a popup has appeared and can press OK and it disappears, but at times, though I know there is a popup hiding somewhere, its not findable! When Logic gets into this state, its also impossible to quit, and many of the menu buttons are greyed out. I've tried

- Show All Windows via the Dock icon - no joy

- Moving Logic to a new window - no joy

- Minimising and maximising- no joy

- Moving Logic between screens - no joy

I know there is a popup out there somewhere, but its unfindable! Its ridiculous! All Logic seems to do is to quickly FLASH, but the popup is never brought into the foreground! Anybody else encountered this? The only way out I can find is to force quit, which I generally NEVER want to do - even the quit short cut does not work.

I'm using Logic Pro X 10.10.1, but this was also an issue for me with previous versions. I really hope this is simple, but I'm exasperated. Thanks in advance!