I worked so long and so hard on a project and i saved everything every second …today when i tried to open it , i got a message (( Failed to open map file , This most likely because the map was saved with a newer version of the engine ))
NOT TRUE
i use 4.18 , the newest version
One i press ok , i found my project EMPTY
Pleaseeee what should i do !!!
Hi,
First, make a copy of your project and all its files and store them somewhere safe to keep a reference to them and to be able to at least restore to the current state in case things go wrong! Now, back to your project, go to its directory > Saved > Backup > Find your map, copy it and replace the original map in the Content folder with it. Hopefully, your backup file is not corrupted and you should be able to get your work back.
Hope this helps!
P.S. For future reference, always try to back up your work and keep more than one reference to it.
hi thank you , i am not professional
i made the copy and stored it in a safe place .
i opened the project file > saved > backup … i found a lot of maps which one should i copy ? and what should i do with that copy then ?
So you found a lot of maps and that means you have a lot of backups, which is good! Now, start with the most recent one and copy it (your backup maps are probably already sorted by modified date but if they aren’t, then Right-Click in an empty space > Sorty By > Date Modified, and that will sort your map by the date). Now select the most recent one and press Ctrl+C to copy it. Go back twice to the initial project directory to get to where your project file is. Find the folder named Content. Inside it, find out where your map is stored (i.e. if in your project your map was in a folder named Maps, then go to this folder). In there, you should see your old map. Simply press Ctrl+V to paste that backup map. Open your project and try opening this backup map. It should now restore your work to the last time it was saved.
good , i find my newest map and i get a copy , then i opened that file named Content > Starter content > Maps
and paste it
i opened the project but i didn’t fined it
Are you sure you’re going to the right folder? I just tried copying a map to my project and it immediately showed up! Make sure that you copy the one reference WITHOUT BuiltData in its name. For example, if your map is named “MyMap”, then copy the one that is named MyMap_[saved-date].umap not the one that is named MyMap_BuiltData_[saved-date].
THAAAAAAAANK YOOOOOUUUUUUUUUUUUUUUU SOOOOO MUCHHHHHHHHH , I restored my work finaaaaaly
i can’t find a word to thaaaank you , what is your name ???
And please consider marking this question as “resolved” to helps us better filter unanswered questions. thanks 
Btw would you like to show your work to us when it’s done? I myself admire all artworks!
of course , My name is , Once i finish i will show it to you , and if anything happens please allow me to call you again
btw how can i mark this as solved problem ?
Nice talking to you You can simply leave a comment on this post or use my handle and I will try to reply as soon as I can 
I had the same problem in 4.18, but luckily I had a backup.