Well, a pgn is just a text file. While you are waiting for system to be fixed, you can save your pgn's like any text file.
Also seeing "Resources not found" error when trying to save to library

I've seen multiple posts about this, but no resolution. Chess.com - please let us know how to avoid spending time analyzing a game and then being unable to save.
That should only happen if you're loading from a Library Collection and trying to use the Save option to save updates.
Staff are aware of the issue. Until it's fixed you should be able to add the updated Gane back to the collection and delete the old outdated one.
I've seen multiple posts about this, but no resolution. Chess.com - please let us know how to avoid spending time analyzing a game and then being unable to save.