What does script signature verification failed mean?

Not sure if this is the right place to post this, but Roblox seems helpless.

For some odd reason Roblox keep giving me a "Script signature verification failed" error in the output when ever I try to load a game to edit.

I tried to switch accounts it is still happening, so I tried to reinstall studio and it still happened. Anymore suggestions?

I can't open my game, it all started when I went and downloaded like 3 or 4 plugins. Two from Clonetrooper1019, two from Stravant.

Help please