So, I was trying to build a custom city. Everything went well until I added a bridge and a few trees. This caused my editor mode to always crash, like, every 20 seconds. Attached is a picture of my city/camp.
Thanks!
Does your bridge have more than one Rigidbody? I know that Many Rigidbodys with Kinematic enabled tend to mess things up a bit. Also the newest version of Unity is out, version 5.4.2. This fixed a few problems for me. Also if your trees have Rigidbodys with Kinematic enabled, that I think can be a problem.
Hope this helps, or that you find something else that does.