I've carefully follow the instructions to import
at-chess-dummy-content-like-demo.wpress demo theme.

Version PHP:8.0.27
MySql 5.7.42-45-log

After I have launched the file import first step with % is ok,
than a window with Control of compatibility of extension appears...
And the process does not go on!

Normally the space should be ok.

I've already upload some text and images with demo version and now I want to use content like demo (but i do not want to loose or erase my job and contents uploaded).

Can you help me?