I dont know if it will help you but i just had an issue with my maps, the things i didnt push on the server of Unreal Revision Control during my last time i work on it was lost.
Apparently after the last UEFN update , UEFN lost the path to my local project so when i double clicked on the project to open it in the project browser, it had sync from the last version available on the server, and it create and copy a new folder locally on my PC so my last local work was not here.
But in my case, it create a new folder and my old project was still in the original folder.
So maybe try to browse manually to the folder of your project and open it like that by finding your original " .uefnproject ", it will open your last local version and not copy the last push from the revision control.
In my case my project was call for example “testmap” and it recreate another folder call “testmap_” but the original “testmap” folder which was my original project was still here and not overwritten.
Maybe it well help you … but it’s just if you have used Unreal revision control and didnt push your update on the server and just keept things locally.
@Vinzant glad you found a workaround for this issue with the project browser - please see the post on @FortniteStatus and keep a lookout for updates there and in release notes for a longer-term fix
I had this problem after the last update. I found in my Explorer two folders of the same Project, in one of the folders was the last Reverse Control in the other folder my original Project I copied from the original one everything in the plugin folder. I hope that helps