Do you see any error messages in the Output Log?
Do you know when this project was created (date)?
Do you know the project id? It can be found in the .uefnproject file in the project root.
Could you share your UnrealEditorFortnite.log and any UnrealRevisionControl*.log files found in C:\Users\<user>\AppData\Local\UnrealEditorFortnite\Saved\Logs ?