I’m pretty sure the chance of it happening does correlate to the number of people in your cabal and/or on your friend list. Normally when you open the friend list window, the game interface draws a table that shows all your friends or cabal members which takes some time on slower PCs or if you have hundreds of cabal members (Agnitio for example has ~500 members). Normally when someone goes online or offline or his/her status changes in someway, the server sends a notification about it to the game client and the table gets refreshed/redrawn. The problem is that this notification system seems to be bugged and often the game interface receives these notifications multiple times each seconds and literally gets spammed by requests to refresh the friend/cabal list table. If the PC can’t keep up with these requests and the game interface receives these requests more often than the time it takes to redraw the table, then the game hangs and crashes.
So Agnitio people made a workaround that disables this auto-refresh feature which seems to fix the issue.
With the consent of the creator I uploaded the mod:
Installation instructions are in the included README.txt