Holes in shadows, after rebuilding lighing. Big mesh.

Hello Guys,

Could you give me idea how Can I solve problem presented on the screen below - small bright holes inside shadows?
This mesh is created based on photogrammetry, and contain about 900k of triangles. Could it be problem?
I set lighting map resolution to 1024.

Your mesh is pretty much unusable, it would be best to retopologize it in your 3D program to use a much lower polygon count and also so that you could unwrap the UV’s better.