Auto-detect sign in issues
Having issues with the auto-detect method (default) then try Adding accounts manually
- Sign out and into each account again (Gmail cookies expire after account inactivity)
- Try Gmail's stay signed in checkbox and it will remember you the next time without opening a Gmail tab.
- If you have multiple accounts just sign in using Gmail's multiple sign-in
- If you delete your cookies (ie. *.google.com cookies) then you will have to re-sign into your Gmail
- Make sure you are not using other extensions which mistakenly block Gmail cookies for privacy or tracking purposes (like Adguard, Disconnect, CCleaner or Ghostery etc.) They may sign you out of your Gmail or try going into its options and see if you can whitelist/exclude *.google.com
- Make sure you have not chosen to Ignore some email accounts in the options
- Make sure you have not chosen to Keep local data only until I quit my browser
- Make sure you have the Latest stable versions
- Did you use the Gmail account activity > Sign out all other sessions? Just sign out and into your Gmail.
- Delegated accounts will not be detected because you are not officially signing into them: other solution.
- Using emails that are not Gmail or custom domains that are not Google Apps then refer to this issue
- Try restarting your browser
- Try restarting your computer (OS updates might cause issues)
- Last resort #1: Try clearing your cookies which might have become corrupted over time
- Last resort #2: Try the Corrupt browser profile instructions