invalid-cert

The following is the GNU All-permissive License as recommended in https://www.gnu.org/licenses/license-recommendations.en.html

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. This file is offered as-is, without any warranty.

Contributions are welcome. See https://savannah.gnu.org/maintenance/fsf/.

Subject: Invalid cert for jabber.member.fsf.org

Make sure that your domain is @"member.fsf.org". So you user name should be "user_name@member.fsf.org". Your client might need its connect server to "jabber.member.fsf.org", but most modern clients shouldn't need that setting.

If you were previously logging in as "user_name@jabber.member.fsf.org" for a long time and you have contact lists, etc. then you might want to keep using jabber.member.fsf.org as your domain so you can keep your contacts and so people can reach you at the same address. In that case, you will likely have to manually accept that certificate. Note that your phone does say that it's valid for *.fsf.org, so that's the FSF's cert.

Please let me know if there are any further issues.