Auto-detect sign in issues
- Use the alternative Checker Plus option: Adding accounts manually
- Sign out and into each account again (Gmail cookies expire after account inactivity)
- Blocking third-party cookies? Then allow this site mail.google.com (Instructions)
- Deleting cookies? (ie. *.google.com) You will have to re-sign into your Gmail
- Disable anti-viruses (ie. Avast) they can cause network issues
- Privacy or tracking extensions can mistakenly block Gmail cookies (ie. Adguard, Disconnect, CCleaner or Ghostery etc.) More info
- Try changing Firefox's Tracking Protection to "Only in private windows"
- Did you Ignore email accounts in Checker Plus options
- Do not set this Chrome option Keep local data only until I quit my browser
- Use the Latest stable versions
- Did you use Gmail account activity > Sign out all other sessions? Just sign out & into your Gmail
- Is your browser closed and still want notifications? Make sure you enable the chrome://settings/ > Advanced > "Continue running background apps when Google Chrome is closed"
- Delegated accounts will not be detected because you are not officially signing into them: solution.
- Using non-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
