The error message is “68206 68206 11:21:25 236.896 ClientSession: Failing reason is ‘A connection timeout has occurred while trying to connect to ‘192.168.0.12’ on port ‘4000’. The issue could either be caused by a networking problem, by a firewall or NAT blocking incoming traffic or by a wrong server address. Please verify your configuration and try again.'”
The article I linked before describes what’s needed. If it’s impossible for you to enable port-forwarding on your router (please follow the instructions of the router’s manufacturer to do that), the better option is to wait for NoMachine Network.
https://knowledgebase.nomachine.com/FR07J02731
Once it is released it will remove the need to know the IP address of the remote computer you want to access as well remove the need for port-forwarding.