I made more complex terrain vegetation scene (grass, few kinds of trees, bushes, some detail meshes), put over whole terrain (2048 height map) and since that, unity crashes very often (5x in 10 minutes). It is empty scene, no scripts, nothing special.
What the fuck? I am starting to be really pissed from absolute lack of testing. Such test is first thing which should be done, there is nothing complex to replicate, just put basic stuff into scene in production ammout.
I put some trees to scene which always perfecly worked. I dont know how much, 10k maybe 20k (it was placed by script)? Framerate is huge, so I dont care and it looks well. And what happened? CRASHING. Even during play mode, 5-20 sec and crash. I delete trees, and OK again.
Probably not memory leak, because during crash there is allocated something like 600-700MB of memory.
This is quite easy to reproduce, just make some good looking forest on bigger terrain. I find out, that just trees are enough to start crashing unity. And there is no reason, framerate is high, so terrain engine is far from overloaded.