Game crashes should IMHO be reported always as priority 1, as they are game destroyers. Did you do anything in particular before it happened, or did you just walk around? Also, what terrain / area were you in?

attached .err file

Did you use a game saved in some much older version of ADOM?

The message indicates that ADOM is searching for the "Rolf palace yard". I image this problem might occur if you try using a saved game from an ADOM version before that level even was implemented. As a workaround I have implemented a different internal behaviour (because the game is trying to ascert if you visited a specific level - a better default behaviour is simply to state you didn't if the level is unknown for whatever reasons).

That's it. I had saved a PC right after char creation in Steam r72, v2.2.6, and brought it into Standard r88, v 3.0.6. The game behaved nicely and created a .bak right where I was.