VPN Error 800 “Unable to establish VPN connection” is a common issue that occurs when working with virtual private networks. Unfortunately, this error code does not provide an explanation for the connection failure.
How to Fix VPN Connection Error 800 – No Server Operating System
To determine possible causes for this error, check the following:
Check that the network connection between the client and the server is working properly. You can try pinging the server if you are unsure, although VPN servers can be configured to ignore ICMP requests.
Retrying the connection after waiting a minute or two can work for sporadic network outages. Trying a connection from a different client device can also help determine if the connectivity issue is specific to one client or if it is a widespread problem.
