reg delete "HKCU\Software\Microsoft\Terminal Server Client" /f Error 0x12 can occur if the remote PC uses an invalid or self-signed SSL certificate.

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters] "AllowEncryptionOracle"=dword:00000002 Create the CredSSP and Parameters keys if missing. NLA mismatches can cause 0x12. microsoft remote desktop error code 0x12

Microsoft Remote Desktop Error Code 0x12 Page

reg delete "HKCU\Software\Microsoft\Terminal Server Client" /f Error 0x12 can occur if the remote PC uses an invalid or self-signed SSL certificate.

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters] "AllowEncryptionOracle"=dword:00000002 Create the CredSSP and Parameters keys if missing. NLA mismatches can cause 0x12.