When I press "run" buttom, there's no response, no warning or error. Nothing seems to have happened

And when i press "pause" or "run" again, the program stucks.
I'm sure that's not my programs' fault, because they ran well yesterday

Hi! Glad to have you on the forums.

Have you tried restarting the IDE?

oh thank you! I found it was VPN problem.
Once I disconnet our school VPN, it works well. :exploding_head: