Ok so I was working on a little sleep animation script, when suddenly I started getting these errors. I deleted my script and started a new one, and now any new script I create has this error. I never edited Actor.psc! It's still dated feb 8th, so I know I didn't touch it. Now if I create any new object reference script, it immediately gives me this error before I can even write any code.

Starting 1 compile threads for 1 files...Compiling "newscript777"...c:\steam\steamapps\common\skyrim\Data\Scripts\Source\Actor.psc(436,28): unknown type idlec:\steam\steamapps\common\skyrim\Data\Scripts\Source\Actor.psc(439,38): unknown type idleNo output generated for newscript777, compilation failed.Batch compile of 1 files finished. 0 succeeded, 1 failed.Failed on newscript777

I have no idea what happened, but now I can't do any modding, and I don't really want to do a steam restore, I have lots of scripts I've done work to.

It would help if you posted an example of your failing script.

I think you may have accidentally deleted Idle.psc

If so you can just make a new one.

Scriptname Idle extends Form Hidden

Ok that was it! Thanks so much. It looked like an empty useless script so I delete it.