RDP Troubleshooting for Azure Virtual Machine
Point 1 : Is the Machine in Running State?
Point 2 : Check If RDP port allowed, Default RDP port is 3389.
Point 3 : RDP port may be allow but there may be deny rule. Incase of 2 conflicting rules, the one with lower priority takes precedence.
Point 4 : Check Boot Diagnostics screenshot, what screen is the machine at.
Point 5 : VM Ip can be found in overview tab may show the ip of your load balancer.
Point 6 : Try to login with VM's pvt IP from another machine on same subnet.
Point 7 : Set RDP port from Run Commands.
Point 8 : Reset RDP Cert.
Point 9 : Azure Health status page. (status.azure.com/en-us/status).
Point 10 : Resources Health.
Point 11 : Try Restarting the machine.
Point 12 : Reapply & Redeploy
Point 13 : Does it prompt for username/password?
Point 14 : UserName Format
Domain\username
.\username (this is for local admin)
Point 15 : User account does not have RDP permission.
Point 16 : Network Level Authentication error ( for this just disable the NLA from the run commands).