ZBrushCentral

Crashing on 'Groups Split'

I have imported a mesh with goZ from dazStudio ( mesh is dawn from hivewire3d )

I click polygroups -> auto groups with uv
I change uv maps resolution to 4000
I click polypaint -> colorize
I subdivide 2-3 times

I polypaint the mesh
Lower subdivide to base
click ‘subtool > groups split’

and it crashes every time

Is this not proper way to polypaint hi res textures ?