Ok seems i finally found what caused the crash.

i had a couple of actors were i randomly select a different model at start, like some roof borders and one bigger piece, but i had a niagara particles component attached too, si i can have the effect of the flames engulfing the module.

Probably after the game choose a different model then the one inside the actor, the game crash when the Niagara component find a different one.

I removed the two actors and remade childs as the other, and the crashes finally stopped.

So i'm polishing and troughtfully testing the actual version for any leftovers and the new update should be ready in a matter of days. Whish me good luck that everything keep goin' well :D