I see the same message. It doesn't have any obvious effect on gameplay, though - the skill choice screen appears immediately after dismissing the error and the game continues seemingly as normal.

One further note: it's not just the first time the PC levels up. It may be every other time - I saw this message going from level 1 to level 2, not when going from 2 to 3, but I saw it again going from 3 to 4. So maybe the program is only attempting to chooseProfessionForLevelGain every other level gained?

I got it going from 1->2 but not since then and am Level 7 now. Not sure what is up with it, then.

It's just a code stab, I'm sure. When Creator will implement professions, there will be a new choise window. So it's not completely a bug.

Strictly speaking I don't think this is a bug, it's probably just a missing feature.

I'd say it qualifies as a bug as long as that code stub for that function is not in place and the error message pops up. Calling an unimplemented function is always a bug, IMO. Putting a code stub in place (even one that does absolutely nothing except return) to prevent the error message would be a fix for the bug, and from that point it would be only a missing feature.

Removed. Please let me know your real name at creator(at)ancientdomainsofmystery.com in order to add it to the credits.