After adding a domain user to a computer over a VPN, I encountered this error. When I logged in as them and tried to connect the VPN, I received the error message “The computer must be trusted for delegation and the current user account must be configured to allow delegation”. I assume this was because they hadn’t authenticated to the domain with their account on this computer yet.

**Be careful when using Registry Editor as you can corrupt your system.

  1. Press start and enter regedit.exe, press enter to open Registry Editor.
  2. Go to HKEY_LOCAL_MACHINE\Software\Microsoft\Cryptography\Protect\Providers\df9d8cd0-1501-11d1-8c7a-00c04fc297eb
  3. Right click and select new -> DWORD (32-bit) Value
  4. Name the DWORD “ProtectionPolicy”
  5. Right click and select Modify…   
  6. Enter 1 as the value data and press OK to save.
  7. Try again now and check if it is working. This may not work for every situation but did work for me.