Failed to connect to kriesi.at port 443 after 10009 ms

Hi, I can’t install a demo. I keep getting this error:
Error accessing file for download:
cURL error 28: Failed to connect to kriesi.at port 443 after 10009 ms: Timeout was reached

We have increased the memory limit and loading time, but it’s not working.

Between my accounts and those of my clients, I have about 20 pages with the same theme, and this is the first time this has happened to me, and they are all on the same web server.

I tried to install the HOTEL demo manually, but it’s impossible; we don’t have enough knowledge.
Thanks!