My comp conf is Core 2 Duo I3-3220, 8 Gb, Gigabyte GTX 570
Win 8.1 64-bit.
On another comp it looks the same.
I attached the .skpТиски.skp (818.2 KB)
You are viewing the model in Parallel Projection. Probably you have been zooming and orbiting back and forth so that the camera is now somewhere either very far away or inside the model. If you switch your camera to Perspective and then Zoom to Extents everything starts to look normal again. You can then switch back to Parallel projection, but I recommend that you learn to work in perspective view - after a while it will feel more natural, and, SketchUp really works best in perspective. In parallel projection, the behaviour will repeat itself after a while, as there is nothing to hint where your zooming and orbiting takes the camera.
Anssi
It doesnt metter in wich mode i working - parallel or perspective view.
The look is the same.
But i’ve solve the problem by copy and paste all objects to new file.