When I go to the armory and remove one of the weapons out of the set, it falls out of the armory and goes into my inventory. In the same time this weapon loses all of its mod crystals. Sometimes this is sad because some of them are very expensive. Is it possible to remove a weapon out of the set without this will happen?

I agree, it's hard to see - if you click 'remove' it will remove the item from your armory. If you click the item or uncheck the box underneath the tier, it will only remove it from your set.

Thank you so much! This will help me a lot ❤