Stop sign turned into square?

The stop sign button turned into a red square for a moment. What's up with that?

Mine is a small tiny Stop button compared to the other buttons...maybe its your screen size?

holding left click on it turns it into a square, so its a feature. but what does it mean?

I got un-suspended....
I'm going to talk to everyone when they are online.
Tbh, I think its the screen size settings, thats what happened to me...

i dont think screen size settings change the shape of a button

They did that to me, the stop button didn't look funny until I adjusted my screen size-zoom...

my screen size is the normal one

Is it at 100? My screen size is 110..

mine's 100. though I think that it's a feature

It means that [scratchblocks]when <> :: control hat[/scratchblocks] blocks will not run. Click the red square to turn it back to an octagon and allow the whens to run again.

Thank you, @snapenilk, good and correct answer!