"Failed to open map file" after crash. How to fix?

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 This is most likely because the map was saved with a newer version of the engine.”

This happened when I tried re-opening the map after UE5 crashed due to VRAM being full. I’m using the latest version of the engine, v5.3.2

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I found a solution that worked for me.

  1. Go to your project folder (Exp.- Documents>UnrealProject>MyAmazingGame)

  2. Open the “Content” folder and find the .umap file that corresponds to the map/level that won’t open (Exp.- “Level2.umap”)

  3. Copy this .umap file and save it somewhere on your PC. This is just a precautionary backup. Now delete the original file.

  4. Now, in your project folder go to Saved>Autosaves>Game and look for .umap files that have your map/level name followed by “Auto”. (Exp.- “Level2_Auto3.umap”)

  5. Look at the dates the umap files were modified, select the latest one and copy it.

  6. Go back to the “Content” folder and paste the file there.

  7. Edit the file name to remove the “_Auto” and any number that came after. The name needs to be identical to the .umap file that you backed up at the beginning of the process. (Exp.- Change from “Level2_Auto3.umap” to “Level2.umap”)

  8. Open your project in UE5 and attempt to open the map/level. It should work now. If it doesn’t, go back to step 4 and try with the second latest .umap file.

3 Likes
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Thanks for this! You’re a lifesaver…

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You just save my 5months of work APW. Dude you are really a lifesaver