Yosemite Active Window Fails

[TonyC28]

This is kinda hard to explain, but when I am working on something in the foreground, i.e Safari, Word, Mail, occasionally the window in the foreground will gray out and act as though it is not the "active" window. So I will then have to click in the window to "wake it up" and make it the active window again. This just started happening after updating my girlfriend's Mid-2012 MacBook Air to Yosemite. Anyone else seeing this?

 

[alkar]

I think I had this bug too multiple times...

 

[TonyC28]

I think I had this bug too multiple times...

Any solution?

 

[TonyC28]

Turns out it was a printer driver type thing from school. Apparently it was broken by Yosemite and kept restarting itself. Not a problem with Yosemite but a problem with the printer service.