"Audacity failed to read a file in C:" Ran out of space when editing audio, any way to recover? Unable to even open audacity

If you have an aup3 file you can’t open you can try the recover procedure here: Corrupt or Otherwise Broken Audacity Project Recovery

You may have problems getting Audacity to open if you have anything in the Windows: C:\Users<your username>\AppData\Local\Audacity\SessionData directory. If you have an unsaved-aup3 file, you can try renaming it to .aup3 then try the aforementioned procedure.