How do I solve this issue : SSL_ERROR_BAD_CERT_DOMAIN with Google. It just started after I upgraded my modem
Are you using a proxy or VPN?
You can check the connection settings.
- Settings -> General -> Network: Connection -> Settings
If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.
See "Firefox connection settings":
You can do a malware scan just to be sure.