When Google Postmaster Tools is not working, several troubleshooting steps can be taken. These include trying a different browser or clearing cache/cookies, checking the Google Workspace Status Dashboard for outages, waiting for a few hours to see if temporary glitches resolve, ensuring the correct Google account with necessary permissions is being used, and attempting access via the API if the UI is broken. After implementing changes, waiting 24-48 hours before rechecking is advised. If problems persist, contacting Google Support, or checking the settings to ensure all features are turned on for the account are also suggested. As well as the workaround of 'picking a domain' in settings.