Premiere Pro won't save

So I've had this problem a few times, and before it went away on it's own but I'm not sure how it solved itself, and I'd like to avoid this if I can so I don't waste time losing progress because it didn't save!

Every now and then I'll get a notice that says "You do not have write access to the directory where this project is located. Select 'Save As' from the File menu to save the project to a new location." But every time I try to save it to a new location, I get no progress. Instead, I get another notice that reads "An unknown error occured while saving this project. Select 'Save As' from the File menu to save the project to a new location."

How do I take care of this? I don't want to lose my progress on this project!