Here's what it says:

Hmm. We’re having trouble finding that site.

We can’t connect to the server at ad.doubleclick.net.

If you entered the right address, you can:

   Try again later
   Check your network connection
   Check that Firefox has permission to access the web (you might be connected but behind a firewall)

I did not see an answer to the question but did removing ad blocker work for you Ezepp?

Hello

What to do if a site seems broken https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop#w_what-to-do-if-a-site-seems-broken

hosts file ?

By way of illustration hosts file https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues#w_remove-specific-entries-in-the-hosts-file-advanced-users