You can break them all day long if you’re writing your own (invalid) json values in lieu of trusting the designer.
Had this happen to me too.
Enter my amazing, extremely shy coworker 
@Cmucci
He checked Version History, spotted a current draft at the bottom, went to the top toolbar overflow menu → Discard Draft. Draft cleared, refreshed, and the map sprang back to life like nothing happened.
If this saves you, please thank my amazing, shy coworker so he’s encouraged to post more.
Tag @Cmucci and remind him it’s safe out here.
4 Likes
Come on @Cmucci! What’s the worst that can happen? We’ve probably all regretted a post or three. You won’t have to stay in the box for TOO long 
Must be new. 2025.1.11 sure doesn’t have that.
I guess I have to do some commits.
Nope, all I can do is restore something from there.
If you’re on 25.2 there is a “Discard Draft” option in the AppStudio landing page.