white strange rectangle stuck on the preview windows
Dear Guys....
I have doing this project for two weeks, but today when I finished one of the comps inside the file, it shows this strange white box on my preview windows....
No matter I deleted what I have made today, it still there...., and if I open other files, it still here too!
However, when I change resolution to FULL mode, it will disappear. How can I solve this problem? It makes me feel nervous...
Thanks for the help...

