From: Melbourne, Australia
It works now.
Before, when you attempted to open the Massage in a separate box, the entire box would vanish.
So, I deleted the Command.ini file, and then restarted the game as I had previously proposed. The ini file regenerates itself, and this time the screen was able to display the switch button.
So, something must have been left over (possibly because I had last played the game (before Broken was installed) in the Raw Message mode. I don't know what caused it, but it now works.
If anyone else experiences this issue, it can apparently be fixed by deleting the ini and restarting the game.
The log window position [MessageLogWindow] wasn't recorded in the INI, but the log window option [MessageLogInWindow] was true. So it was crashing on trying to position the detached log window.