Im trying to address this properly so i dont get yelled at. Here.
Refresh case sensitivity failure. Asset: Assets/Levels/Images/._Main Level.png ; Assets/Levels/Images/.MainLevel.png.meta
From google it appears that this error related to invalid or incorrect meta data. Have you moved the project folder between operating systems or moved the entire project? Zipping and unzipping may also be related.
One option would be to locate the file at Assets/Levels/Images/._Main Level.png in a file explorer. Delete the file and see what changes. The file may be hidden.