is a "textual GUI" front end to mason, the interactive firewall builder. When it is run, it allows you to control mason's behavior through simple keystroke commands. It can start and stop mason, allow you to edit the rules generated (and re-merge them into the currently running rule set), and change mason's settings. It also has a "console lock" setting for locking the console down if necessary.
Default behaviour of mason-gui-text ist to exit if another instance of it is already running.
Try to stop other instances of mason-gui-text and continue running