Tested in a new environment, not specific to whisky, Webber can trigger the error too and this is how you can replicate it with a friend:

Server must have:

PvP Enabled
Wirra Mod (Obviously)
2 (or more) players

c_spawn("monstermeat",4)
c_spawn("spider",4)

Webber feeds the spiders to tame them.

Wirra places her two hound plushies she spawns with

c_spawn("hound",3)
c_spawn("firehound",3)

Neither player should have to do anything after that, the game will crash when the hounds and spiders begin fighting.
For safety incase the spiders are dying too quickly for the crash to occur, use c_spawn("spider_moon",4) instead.

Thank you for your report. The problem area was identified and addressed.