Replay

Put the summary of the bug you're having here   Replay Thumbnail Bug

What I expected to happen was...:
After pressing shortcut "n" (Thumbnail) after that it should work normaly 

What actually happened was...:
After pressing shortcut "n" (Thumbnail) it went in black screen

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
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