Hi Hoangduong,

I'm frequently confronted to this problem when I use the stamp tool.
For me, it happens when i have other objects near the surface I want to stamp and when my model become too large.

To avoid this, there's a few solutions :

Try to put all others objects in a turned off layer Take your surface and your building print out of your model, and do the stamp in a new file, and then copy it in your model (not always possible...) If you have an old version of Sketchup 5, save your file in the SU 5 format, do it under SU 5, and reopen it with SU6. It never crash on sketchup 5 for me.

Hope it helps you.