Dropped instances of... crashes editor

[brainiac]

This is the most common line in game.log (only different number).
<WARNING> [instancing] Dropped 29900 instances of '/model/vegetation/grass/sc_grass_green1.pmd' exceeding the per-item rendering limit (65536). Reduce instanced model density or increase instanced model (grass/tree) variability by using profile with more model types.
Why that crashes game? There is no other errors.
How to fix it? I am currently just converting DLC Scandinavia roads to FLD's on Rusmap.

[ScuL]

Reduce your grass settings

[brainiac]

Thank you.