When I try to union this happens sometimes 
or this 
What’s the problem? Is it the shadows?
no its supposed to looks like this lemee show you 
and i am union because of these lines 
So, you’re unioning to remove the lines?
What’s the problem that you’re trying to solve?
the problem i am trying to solve is how should i union without it doing the stuff above with the squiggly lines
why are you unioning it when you already have the desired result? considering that it adds those lines, it probably adds polycount too. if you just want to have it neatly organised, you could use a model.
I dont i still have a lot more and when i try to union all of it at the same time my studio crashes.
how many objects are you unioning? and are they meshes, or a lot of the standart parts?
standard parts 30charssssss
you can just exend those parts to your needs and put it into a model. but if you try to union it you need them to slightly overlap perfectly so it Zfights, for the best results if you union it. at the moment, there should be space inbetween each part where the line forms