Unable to login with facebook and twitter

Sorry for the delay. We've found where that warning message is coming from. However, it shouldn't be causing you any problems. Can you confirm if any actual issues are arising, like not being able to login or fetching any of the user's profile information?

If everything is good, that warning can be hidden by setting the "Error Reporting" to "None" in the Joomla Global Configuration area. We'll also update our code in the next release to properly avoid that message from happening in the first place.

Let me know about the above, and thanks for your patience,
Alex