Hello ppeixoto,
There may be a lot of issues causes that you received 138 error (ERR_NETWORK _ACCESS_DENIED) while connecting. All are related to network configuration. To check where a problem is, please go through following steps:
– Check if your external IP on server host is the same like indicated by NoMachine Client (Server Status window from your screen). You can check it for example on https://www.whatismyip.com/.
– Check if you can ping external IP of your server host from your client host.
– Check on router if ports which you use to connect using NoMachine isn’t blocked.
If your server is behind a NAT router or a firewall it’s possible that you have no UPnP enabled on your server side router. In that case please follow https://www.nomachine.com/AR11L00827 article.
Regards.