System.UnauthorizedAccessException: Access to the path '7996'... What is this?

I’m in the process of learning how to make plugins. So beginning with the tutorials online I’ve hit a road block.

When re-building the project

C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets(42,5): error MSB3075: The command ““C:\apps\Epic Games\4.11\Engine\Build\BatchFiles\Rebuild.bat” {some .cs file} Win64 Development “D:\Users…\Desktop…uproject” -waitmutex” exited with code 5. Please verify that you have sufficient rights to run this command.

When building the project

C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets(37,5): error MSB3073: The command ““C:\apps\Epic Games\4.11\Engine\Build\BatchFiles\Build.bat” {some .cs file} Win64 Development “D:\Users…\Desktop…uproject” -waitmutex” exited with code -1.

Done so far:

  • Reinstalled Unreal Engine (4.11.2)
  • Reset Visual Studio (2015) to default settings
  • Ran Unreal Engine and Visual Studio with admin rights

How to fix this error?

1 Like

I managed to solve this issue and thought I would post it.


  1. Go to C:\apps
  2. Right click “Epic Games”
  3. Under the General tab, unselect “Read-only”
  4. Hit apply
  5. Open the visual studio project and build/rebuild

Hope it helps

1 Like

It worked for me…

This did the trick for me, somehow after adding the source to my perforce folder, the folder changed to Read only.

So just select your source folder => Right Click => Properties => Unselect read only => Build


Thanks for the tip!
In may case, it worked after unchecking the read-only from the Binaries folder.

1 Like

Thanks, unticking Binaries folder works.