Unclear messaging when trying to make changes to a project when two instances of the project are open at once

If a user has a project open more than once, they will be given an error message when trying to save changes. This message could be more clear as to what issue has occurred.

1. Open a project
2. Create a new level
3. Save all
4. Close the project
5. Open the project twice
6. Make a change to the level that was created earlier (in only one instance of the open project)
7. Save all

Result: A popup message is given (Example: The asset "/Game/Untitled" (Untitled.umap) failed to save[Image Removed] (see attached image for example)
Expected: A more clear message would be given, letting the user know they should make sure that they do not have more than once instance of the editor open and then to try again