Use the group policy settings changes described below to rollback the changes to ‘Vulnerable’ state to allow RDP access.
1. Open Group Policy Editor, by executing gpedit.msc
2. Policy path: Computer Configuration -> Administrative Templates -> System -> Credentials Delegation
open COMMAND PROMPT
Run gpedit.msc and expand Administrative Templates
3. Run the command gpupdate /force to apply group policy settings.
4. Your remote desktop connection will be working fine now.