Thank you, but there are other main problems.
I installed Librecad 2.2.0 under WIN10 and tried to print a square of 10x10 cm on the DINA4 paper. This exercise is really quite simple and you can't really do anything wrong. It does not work.
In the settings, centimeters were set as the main unit.
In the drawing sheet, a square the size of a grid ( 10 cm) was drawn using the Rectangle function.
After opening the print preview, a square appears that covers the entire DINA4 page.
In the Scale window, 1:4.7619 is displayed. After changing the scale to 1:1 and pressing return, the print preview turns gray. The white drawing sheet has disappeared and becomes visible as an empty sheet at another place when zooming.
Several attempts up to a repeated reinstallation of the software remain without success.
It seems that the software does not work correctly.