will having two precipitation effects crash a map? like could i have snow and rain?

Best way to know is to try it and find out.

it works, just my map was crashing without an error, but that wasnt it.

EDIT:

whats weird is that the effect for rain hitting the ground is there but not the rain, only snow.....

Probably you can only have one at a time, but having two doesn't crash it: just one is ignored. Now, I don't think snow has an impact effect, so the only impact effect you have loaded is the rain one. The snow fall effect, however, is cancelling out the rain one. So, you have snow falling and rain splashing.

But that's just a vague guess.

that seems about right.