In the process of subbing, I hit a ctrl or fn something, something to split the screen like this. Any help for getting the subbing part back to where it should be? ACK!
It’s zoom, zoom out 
The screen shows 90% zoom, maybe try to put it back to 100%
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Brilliant! (Ctrl + or - for those who don’t know the manual zoom keys 
) THANKS!
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On some mousepads you can just expand with 2 fingers without the keys
Your are not the first who got that scare 
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#macbookproblems