Failed to Open Descriptor File

Hello Everyone.

So, UE4 is starting to get on my nerves.

I seem to have yet ANOTHER engine/project breaking bug and therefore the game I’m working could not be released by it’s deadline.

Anyway, I keep getting this error whenever I try to open a packaged product.

The error states:

“Failed to open descriptor file '…/…/…/Myproject-Win32-Shipping/Myproject-Win320Shipping.uproject”

Any ideas on what to do about this (other than scream uncontrollably)?


~ Jason

I also get this bug but only in blueprint projects , code projects seem to work …

Development builds seem to work however … i even tried uninstalling and reinstalling the engine but the problem is still there …

I think a have a workaround to your problem …

but your assets will be exposed in this case

if you go to project settings packaging you can remove the use pak file option

you can then go (after packing again) to the game’s folder (inside windowsnoeditor) and rename the project’s folder by adding -Win32-Shipping next to you project’s name
inside this folder you will find a uproject file that you must also rename by adding -Win32-Shipping next to the project’s name you will then be probably able to run the game by running the
Win32-Shipping.exe file inside the binaries folder

IT worked for me but as i said before your assets will be exposed

This is probably a naming bug of the packaging automation tool

Alright so I find a really weird way around this…

You just need to package it as a Development Build and it works…

I really have no idea why this is a solution.

The assets aren’t exposed as well so that’s a plus.

Thanks for the information though.

I really hope we get a fix for this in the next build of the engine.

~ Jason

All I did you unticked, repackage and it worked.


I wrote this for those who already have done all the other procedures and gets endless pain from the ‘Failed to open descriptor file’ error at application executing.

No one has mentioned this ‘permission’ problem, and also default UE process doesn’t touch this part. I hope it help android beginners.

Just like that video’s 17:50 part

  1. Check phone USB linking state (Of course ‘USB debugging mode’ & ‘adb devices’ checking has proceeded.)
  2. Run that ‘.bat’ file
  3. Play application at phone
  4. Now, phone ask you to check permission of ‘file access’. Touch it
  5. profit

I got this error launching to my android. I just deleted binaries, saved, intermediate, and derived data cache folders (I guess you don’t have to delete them all to fix it but), uninstalled the game in my android, restarted my android, restarted unreal, and it worked again

This replay may help someone who moved the entire project to another folder, and this error came out, try this:

  1. regenerate the project solution file,
  2. open the solution in visual studio (make sure the extension UnrealVS installed),
  3. change the path of uproject file to the new one in UnrealVS command line.

Hope it helps.