I found a bug. I don’t know how I done it but I made so the 3D cursor is the center all the time. I can move the cursor to another place and it become center where the cursor is. Damn. How do I fix it?

If you mean the 3D cursor is now the pivot point for rotations, you have probably pressed the period (.) key accidentally. Use commaKey (,) or Ctrl-, to change rotation center to Bounding Box or Median Point, respectively.

You can also change these from the dropdown menu called Pivot: in the 3D View header

Thanks it worked.