I see. Thanks for the screenshot, that's extremely helpful! The reason this happens is the file "scriptinfo" got corrupted. You can see it's entirely empty.

That file has some some script metadata, but it's only needed to show the list of local scripts, not to run them. There really is no "fix" besides redownloading them from the Online tab. Sorry about that.

It is curious that so many people got the bug at once, but, maybe it was always around and it's only getting reported now.