Hello,
First off, thanks for reaching out to us. You could have reached out to us using our Support Forum or the support link. We always try our best to reach our users and help them fix the problem.
So please, try to contact support before writing here with a poor rating.
I wrote to you twice. You do not answer.
The local XAMPP server does not work well with importing demo content. I installed Open Server Panel and the demo imported without errors. Now everything is all right.