Ok here is how I fixed my current issue. Please note this happened only when my engine crashed and I forgot to restore when logging back in. Once in your unreal engine go to “FILE” scroll down to “RECENT LEVEL” Your level should be right in there! Open it up and let it load once it is loaded again drag a new prop into the level and “SAVE AS” Give it a new name and it will be back on your level selection when loading up going forward! Please note this works the best when you are using the “Autosave” function which everyone should be using. If you go to your file where all your levels are and start messing around with them. They may never load on recent level or crash when trying to open it. The best thing to do is " Save to favorites and make back up’s on another external hard drive! I hope this helps people and keep on building!