generator not running, error retrieving URL

[trand1]

I get this error output, but the URL clearly works:

index.php?op=config&errmsg=There was an error while retrieving the URL specified: [ External links are visible to forum administrators only ]
HTTP Code:

HTTP headers:
x_csize: 0

HTTP output:

[trand1]

I'm attaching my generator.conf file, and would really appreciate some help on this.
I have about a dozen other websites using this with no issue and don't understand why this site isn't working.

Also, I don't recall having to add an email and password before (and that is not part of the conf file for other sites); maybe that's part of the problem?

[XML-Sitemaps Support]

Probably there is a configuration problem - it looks like your server doesn't allow local network connections via port 80 (http) or 443 (https) - as a result sitemap generator is not able to crawl the site. This is usually related to firewall installed at the host - could you please contact your hosting support regarding this?

[trand1]

My sysadmin found and fixed the problem.
Although the lets encrypt cert was working (i.e., the site was working with https), there was a validation issue with it so they regenerated the cert and voila!
Sitemap generation is now working.