When you are trying to connect to a Remote Desktop (on a VPN) and get the above error on a Windows machine, one way to solve the problem is as follows.
- Open RegEdit
- Take a backup of the entire Registry (Export) so that you can revert back, if required.
- Navigate to
HKEY_LOCAL_MACHINE > Software> Microsoft > Windows > CurrentVersion > Policies > System
- Right click on System, select New > Key and name it as CredSSP.
- Now right click on CredSSP and create a key – Parameters.
- In Parameters, create a new DWORD (32-bit) value with the name AllowEncryptionOracle.
- After creating the file, right click on it and Modify.
- Set Value data to “2” and Base to “Decimal”.
- Click OK
The error should have gone!