Undefined array key "OA_SOCIAL_LOGIN_REGISTER"

[TakeOwer]

Hi,
I would like to point out that I have installed the latest version of this extension. When a user connects via social media, vimeo, google, microsoft etc... This error message appears:
[ROOT]/includes/functions_user.php on line 2933: Undefined array key "OA_SOCIAL_LOGIN_REGISTER"

Line 2933 contains this code:
if ($default_groups[$row['user_id']] == $group_id && (!isset($temp_ary[$row['user_id']]) || $group_order_id[$row['group_name']] < $temp_ary[$row['user_id']]))

Any suggestions to resolve this error?
Best Regards
Salvo