scores no longer saving

We need more information to even begin to help you. What is your computer's operating system and version? What version of MuseScore do you have installed? What happens when you try to save a score ... specifically and in much detail?

The level of detail you need to provide should be along the lines of ...
After creating a score, I click here, then select this, then that. I get an error message that says, "Some kind of error message CodeCodeCode"

As mentioned, it’s difficult to help without more info - how exactly you are trying to save, and what exactly goes wrong when you try. but my best guess is, you are attempting to use the “cloud” save feature, but you aren’t logged in, or having no internet connection, or the website where the scores are saved (MuseScore.com) might have been experiencing temporary connection issues itself. My recommendation is not to use that feature but to instead save files normally to your computer. Try File / Save as. Also, if you are already saving logically, maybe there is a permissions problem with the folder you are saving to, and again the “save as” command would be the solution.