I discovered this because the 1.1.1 update broke a mod I host. They added a new line to the monster code. When a game tries to create a monster that does not have this new code the result is a soft crash (unloads the world and instantly sends you back to your ship). On the cmd server log an error is created but I have already figured out how to fix it.

I see you add 2 new monster types:
itemframescriptbug.monstertype
itemframescriptbugB.monstertype

You need to go into these files and simply change these lines of code:
"appliesEnvironmentStatusEffects" : false,
"minimumLiquidStatusEffectPercentage" : 0.1,

Into this:
"appliesEnvironmentStatusEffects" : false,
"appliesWeatherStatusEffects" : true,
"minimumLiquidStatusEffectPercentage" : 0.1,

(the 2 values were taken from your itemframescriptbug.monster)