A few people have had trouble authenticating with version 2.0. Google deprecated the old method called ClientLogin, so version 2 switched over to OAuth2, which is more secure since you don’t have to provide the application with your password.
The most common causes are an application listening on port 80 (a web server, skype, etc.), not allowing cookies and using a proxy.
Please follow these steps if you are having trouble authenticating:
- Update to version 2.0.3 – this version has a fix for the expired token dialog. 2.0.1 change the authentication method so it would work even when an application was listening on port 80 (such as a web server or skype)
- Go to the Menu -> File -> Offline and verify Work Offline is not checked
- Go to Menu -> Options -> Privacy. Either check Accept cookies from sites (Accept third-party cookies can be set to Never) or click Exceptions… and add google.com and click Allow. You may need to clear cookies and clear all exceptions first.
- Disable all other add-ons and restart Thunderbird. Lightning + the Google Calendar Provider add-on have caused this issue in the past.
- Go to Menu -> Options -> Advanced -> Network & Disk Space -> Click on Settings -> choose No Proxy. Restart Thunderbird and try again.
If none of the above works, please enable verbose logging in the gContactSync Preferences, try to authenticate again, then send me the log. Also try clicking on this link in a web browser and see if it eventually redirects you to a blank page with an address localhost/?code=…. That link is what gContactSync uses to authenticate.