Hi, welcome on the board
There are a few maps which doesn't have bot support.
Anyway, your problem happened on oa_dm6, it has bot support. When they don't have, it crashes as soon as the firt bot appears.
So, I don't know what's causing this. Note; some map crash the game if you play like deathmatch while they are meant to be played for CTF, the error is something like "Couldn"t find spawnpoint blablabla".
I doubt it is related with your Tremulous installation, at least, from your logs we can say openarena doesn't seem to load tremulous files.