Users get 'connection method not available' when trying to connect by SSH protocol and NoMachine login on a server host with OpenSSH v. 7.0 installed. This problem affects NoMachine v. 5.x, 4.x and also 3.5.0.
This is due to the fact that OpenSSH v. 7.0 has disabled by default the ssh-dss (DSA) public key algorithm:
and it's not possible to verify the DSA key used for the NoMachine login.
This problem occurs for example on Fedora 23 and Ubuntu 16.04 .
A temporary workaround is to modify the SSHD configuration file, namely /etc/ssh/sshd_config, and add this line at the end of the file:
PubkeyAcceptedKeyTypes=+ssh-dss
Restarting SSHD is requested to make this change effective.
