Well looks like there’s a nasty bug in patch 3.2. It turns out that the invalid action and invalid command sound effects both fail to clean up after themselves which could result in the game crashing. The way I’ve been able to trigger it was to use an alt-command (like Alt-X) when entering an “other” command, or backspacing beyond the start of the command prompt.
I already have a fix checked in and it’ll be released in 3.3.