material instance crashes editor

Hello, I’ve seen some related issues, but was not sure until now If I should submit this question.
I have material, which I use to control meshes outline color and thickness. If it is of any importance, It has two corresponding parameters - a vector 3D parameter, that controls color and a scalar param for thickness (I use tesselation to expand outlining mesh).

Editor crashes everytime I open material instance, if there are opened editor windows with meshes wich use this material instance.

I’ve checked on ceveral PCs and different meshes.
I’ve updated engine, sicne frist time this error occured on 15.1. I’ve verified engine as well.

Attaching logs just in case.

game log

crash log