This has been resolved in MM 2.2.6

Learn how to manually upgrade

Currently, the social login feature will not work unless an email address is returned by Facebook. Most Facebook accounts will have an email address associated with them, but it is possible for people to create a Facebook account without providing an email. In the event that an email address is not provided then the customer will be shown an error page with the error code 1001013 passed to it. 

In order to help customers understand how to resolve this without having to get in contact with you, you could provide specific instructions on the error page informing them that in order for them to login/signup using Facebook they'll need to associate an email with their Facebook account first. This article shows you how to do that step-by-step:

Customize Error Messages on the Checkout Page

Ultimately it will look something like this:

[MM_Custom_Decision code='1001013']
We're sorry, we were unable to complete your request because your Facebook account doesn't have an email address associated. Follow the instructions in this article to add an email to your Facebook account and then try again: https://www.facebook.com/help/162801153783275
[/MM_Custom_Decision]