Sometimes the whole game crashes while playing. I'd say it only happens when
it's up to one of the AI players, but I'm not sure. Today it happened and,
luckily, I had started it from a terminal, so at least I have the error message
to show:

src/globaldata.cpp:834: void GLOBALDATA::make_bgupdate(int32_t, int32_t,
int32_t, int32_t): asserzione "(w > 0) && (h > 0)" non riuscita.

That's the italian message, which translates in english to something like
'assertion "(w > 0) && (h > 0)" failed'.

I don't know if that matters, but it happened while the AI was choosing the
weapon or just after that. The AI tank was under a Super Dirt Ball and the AI
had no more Riot Blasts to escape. The AI looped a bit over its available
weapons and then the game crashed, but I don't know if the AI managed to fire
anything before the crash or not.

However I'm sure other times the game crashed in a different situations,
because it's the first time I manage to cover the AI tank with dirt.

It happened again today with the same error message, but something
strange happened before the crash: I moved my tank to the right edge of
the window and the tank dropped inside the terrain (see attached
screenshot). I fired a small missile to minimize the damages to my tank,
then the game continued and it eventually crashed during some AI turn
after mine.

Today it crashed again, but this time I got a different message:

atanks: src/virtobj.cpp:77: virtual void VIRTUAL_OBJECT::draw():
asserzione "bitmap && "ERROR: VIRTUAL_OBJECT::draw() called without
bitmap!"" non riuscita.
Shutting down Allegro due to signal #6

I don't know if it's the same bug or a different one. It seems both
messages (the one in my original report and this one) refer to something
GUI related, they both happen while playing, they are both failed
assertions and they both happened during the AI turn, but that's all I
have to assume they are related to the same bug.