Can’t Login to NoMachine But Logins Are Correct, Error: “Authentication failed, please try again.”

Case: Can’t connect to NoMachine over LAN due to authentication failure, yet logins are the right ones. Log at /usr/NX/var/log/nxerror.log reveals: Authentication failed with error 7.

Specs

Solus 4.10
NoMachine 6.12.3

Note: Case has been solved with the OS running as guest on VirtualBox 6.1.12; network adapter set as network bridge. However, the solution applies to regular installations as well as it has been sourced from the NoMachine forums and context outside of VirtualBox guests.

Solution

1. sudo nano /usr/NX/etc/server.cfg
2. Ctrl+W for EnablePasswordDB
3. Uncomment it and make sure it’s set to 1
4. Ctrl+X and Y
5. sudo /usr/NX/bin/nxserver –-useradd UserName*
   *where UserName is the user for the OS, don’t create a separate one
6. Specify the corresponding password at the password prompt
7. Reconnect to NX host

Authentication should now be working as expected.

Sources

• NoMachine Forums – Can’t login “Authentication failed, please try again.”