An update released by Microsoft (KB 4093492)on May 8, 2018, for Windows 10 Operation System was targeted to change the default settings CredSSP from Vulnerable to Mitigated.
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
Run gpedit.msc and expand Administrative Templates