monster base

[Tibarius]

I tried using version 4.2.1 to work on a mod.

What i did:
+ monster_base.txt: removed all except @ / Morgoth and then used d/D/A for young dragon, dragon, ancient dragon

+ monster.txt: removed all monsters from DL 3 to 99 except Sauron / Morgoth and changed all remaining "base:..." into one of the three dragon bases "base:dragon" for example.

+ pit.txt / summon.txt: changed all bases to dragon or removed large parts

Game startsup fine, looks like i can use "~ => monster knowledge", but when i cast a magic missile at a monster, there comes a C++ Runtime Library assertion up when the missile hits the monster:

mon-msg.c line 291, race->base->pain != NULL

Is there any non documented requirement for how to modify monster_base.txt?

Like all letters from a to z must be used or something like that?

Anyone a clue, thanks