Missing level map

This might not help Dash07, but hopefully it helps anyone else who runs across this. I had the same issue and was able to “fix” it by deleting the .umap file from \Documents\Unreal Projects[projectname]\Content* and replacing it with the most recent copy found in \Documents\Unreal Projects[projectname]\Saved\Backup.

When I renamed the backup file to match the name of my level, UE4 immediately recognized it, and it showed up in my Content Browser. This copy works without issue.