It seems I have the same problem on my Win 10 home and latest OpenVPN client 3.5.0. I have my VPN server and all worked well for a month, suddenly on PC it refuses to work(connects to the server with no error, but no internet), I believe the problem is with adapter, as I don't have TAP adapter anywhere.
But instead I have according ipconfig
"Unknown adapter OpenVPN Connect DCO Adapter:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :"
Not sure if its made by intention, but OpenVPN uses this instead, managed to track it by Wireshark
Unknown adapter Local Area Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
I had Avast antivirus running, after its removal and reinstallation of OpenVPN it worked well till restart. Now it's all same, I've tried to disable built-in antivirus and firewall but no luck so far. The server seems to be good, I still able to use it on my phone/tv within same network as my PC.
If you have any thoughts what could be the problem would be great to hear.
Thanks in advice.