Maurosh,

After downloading your file, I had a quick look at it, and did a test-render in v3.0 and v2.6. I can't see any problems.

When inspecting the sh3d-file, I noticed that the granite texture (item #89) is 1600x1200 pixels. You might consider making it smaller, e.g. 800x600 pixels. This would make rendering more reliable and faster without affecting the result.

Also, your walls are semi-transparent, maybe this causes strange effects when exporting.

Hans