Failed to open map file. 4.8.3

Hey, I have a very big question about that bug:
“Failed to open map file. This is most likely because the map was saved with a newer version of the engine.”
The problem is that the engine version is latest updated(I mean that I used only this version). And now I have only the black level window, all off assets is currently save, but the level is gone. So, how can I return my level which I already created before. Sorry if my English is not correct

And, now I trying to open my level on 4.9, and what do you think what I got? Same issue, black empty level

Hi EvaFrise,

  • Does this occur in a clean, blank project with no additional content or is it limited to this one project?
  • Did you open the project in the 4.10 preview?
  • What changes were made before this error occurred?
  • Can you show me a screenshot of the specific error you are getting?
  • Was anything added to the map before this occurred?

You should be able to get a backup copy of the map by going to \Unreal Projects\PROJECTNAME\saved\backup, but I highly recommend source control over this approach in the future. Having access to source control will allow you to revert to previous versions fairly easily.

Hi EvaFrise,

We have not heard from you in several days. I am marking this as answered for tracking purposes. If you are still experiencing this error, please comment with the requested information.

“Failed to open map file. This is most likely because the map was saved with a newer version of the engine.”

1: This is limited to only this project. With a new project I have no warning or issue.

2: This project was build on 4.8.3, after this error, I downloaded new 4.9. version and issue still continuous. So, I don`t know what the meter if I downloaded 4.10 or not

3: Before this error just my electricity was failed and PC power off

4: Attached the screenshot of this error, but if it`s not the right screen, please tell me where I can find it

5: Nope, I`m just work with shaders.

Well, this folder: \Unreal Projects\PROJECTNAME\saved\backup\ is empty. More then, full Unreal Projects folder is empty…

Can you send me the project this is occurring in? I’ll be happy to take a look and see what may be occurring.

How can I do this? Can u explain?

If you go to the project folder in your windows explorer \Unreal Project\ and find your project name, compress that to a file and either upload the file here or, if it is too large, upload it to either dropbox or google drive and post the link so I may take a look.

The point is that my project folder is empty. If u take a look on my 1st and 2nd screen, u may see “Soldier” project. But the folder is empty. So, I think my project is done and deleted irrevocably…

Do you have any steps I can take to reproduce this on my end?

Not really. my electricity just failed(collapsed, I don`t know how to say “Power Off”)

Do you have any backups of your project on a source control service such as Perforce?

Nope, Ill been very happy if I have some backups there, but the project is gone, so dont worry about it, just check your engine for the future of this error, if u want, I can sent u my latest project, but I don`t think that he can be helpful for u

I’ll keep an eye out for instances similar to this so we can try to reproduce it on our end. Unfortunately without a reproduction, however, there isn’t much we will be able to do to address the error. If this occurs again, please comment here so we can attempt to reproduce it on our end. For now, I will mark this as answered for tracking purposes.