Openweather extention not working

Found a solution on GitLab from @StephGbzh that just worked for me using 20.04. It is most likely an expired CA certificate:

1. check that you target the right expired certificate

   openssl x509 -issuer -enddate -noout -in /usr/share/ca-certificates/mozilla/AddTrust_External_Root.crt
   

   which will produce the following:

   issuer=C = SE, O = AddTrust AB, OU = AddTrust External TTP Network, CN = AddTrust External CA Root
   notAfter=May 30 10:48:38 2020 GMT
   

2. backup

   cp /usr/share/ca-certificates/mozilla/AddTrust_External_Root.crt ~
   

3. delete

   sudo rm /usr/share/ca-certificates/mozilla/AddTrust_External_Root.crt
   

4. update the system

   sudo update-ca-certificates
   

5. restart gnome shell: AltF2, r, Enter

Another way to fix it without deleting .crt files, or disabling secure http.

In terminal:

Change directory.

cd /etc

Make a backup of this file.

ls -al ca-certificates.conf*
sudo cp ca-certificates.conf ca-certificates.conf.BAK
ls -al ca-certificates.conf*

Edit this file.

sudo pico ca-certificates.conf
change "AddTrust_External_Root.crt" to "!AddTrust_External_Root.crt"

Update certificates.

sudo update-ca-certificates
restart gnome shell with ALT+F2, r, ENTER

Reference: https://gitlab.com/jenslody/gnome-shell-extension-openweather/-/issues/272