Your local system may be having trouble communicating with your DNS server, specifically preventing it from finding the extensions.gnome.org IP address.
Reopen from your applications menu to force a fresh update check. 3. Verify Your DNS Settings Your local system may be having trouble communicating
GNOME Software often attempts to check for updates immediately upon login before the network stack is fully active. Your local system may be having trouble communicating
When you encounter the error it typically indicates that your system’s software manager—often GNOME Software —cannot establish a connection with the remote server to fetch update metadata . Your local system may be having trouble communicating
If the error is caused by a service that didn't start properly at login, killing the process and restarting it often clears the "cannot resolve" notification. Open your terminal. Run killall gnome-software .