ThirdPersonExampleMap.umap failed to save

Hello Everyone,
I just ran into an error I’ve never encountered before and that is when I try to save my project, I get the error message ThirdPersonExampleMap.umap failed to save. I tried looking up solutions but wasn’t able to find anything. If anyone else has had this problem before, please share your solution.

Thanks!

You most likely have two instances of your project open.