Geometry data in my skp file were totally spoiled during drawing process. I removed all geometry from corrupted skp, draw two lines near the (0,0,0) point. If I connect 2 points along green axis with (0,0,0) in the middle I’ll get line and strange triangle. I have corrupted skp file. But I can’t find the way to send it to your support team. Please connect me with my account e-mail.
Actually I don’t care about support now. I’m just ready to provide information about bug in software for free and I don’t care about any feedback from developers about it.
I can’t find any control to attach file to thread.
I reviewed different options and found that there are a lot of hidden geometry (lines). And this unexpected triangle was based on 1 visible and 2 hidden lines. I didn’t try to create hidden geometry (I didn’t even know about it). Maybe some uncontrolled action or maybe they were made by some sketchup tries to fix scene (sketchup reported a couple of times during modelling process that model is wrong and it should repair it).
So I don’t see that something wrong now. Thank you for your help anyway.