Cannot start firefox on X11 forwarding SSH session

I have installed Ubuntu Desktop 16.04.2 LTS and want to start firefox from my X11 forwarding ssh session but I get the following error message:

user@user-Virtual-Machine:~$ firefox Failed to connect to Mir: Failed to connect to server socket: No such file or directory Unable to init server: Broadway display type not supported: localhost:10.0 Error: cannot open display: localhost:10.0 

I am using the latest version of BitVise SSH Client

The settings in my SSH client look like this: click here for X11 client settings

My sshd_config looks like this:

Port 22 Protocol 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key UsePrivilegeSeparation yes KeyRegenerationInterval 3600 ServerKeyBits 1024 SyslogFacility AUTH LogLevel INFO LoginGraceTime 120 PermitRootLogin yes StrictModes yes RSAAuthentication yes PubkeyAuthentication yes IgnoreRhosts yes RhostsRSAAuthentication no HostbasedAuthentication no PermitEmptyPasswords no ChallengeResponseAuthentication no X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes AcceptEnv LANG LC_* Subsystem sftp /usr/lib/openssh/sftp-server 

What am I doing wrong?

2 Answers

I had the same problem while running firefox on an Ubuntu 18.04 system through MobaXterm. Solution was to install xorg and openbox and then logging in again.

Try disabling AppArmor

sudo ln -s /etc/apparmor.d/firefox /etc/apparmor.d/disable/ sudo apparmor_parser -R /etc/apparmor.d/disable/firefox 

ref: