Facebook Connect Not Responding

Thanks for the upgrade but I'm afraid, it's still not working. This is the error I'm getting in the tools tab:

:: Facebook :: API failed to initialize; please check Configuration is correct.

I've inserted the correct parameters in it but I'm still getting the error.
What could likely be the issue this time?

You can ignore the tools check, it's a bug that's about to be fixed with 3.0.1. You need to test if working on frontend; if not you've configured your application wrong or you have a conflict. Ensure you test with debug mode and maximum error reporting set within Joomla global configuration so you can see errors.