I'm using Ubuntu 18.04 and MATLAB r2018a. When I pull up a help window using for example `doc magic` and then close this window with the 'X' button in the GUI, the whole MATLAB GUI freezes. It appears that I am still able to type in them, as evidenced by some of my typing being present upon restarting MATLAB in my *.m file. I am not sure how to debug this further, as it appears to purely be a GUI problem. In the terminal which I used to start MATLAB, there is no additional output.
The only output to the terminal I have appears on startup:
Gtk-Message: 18:05:40.313: Failed to load module "canberra-gtk-module"