Can’t add member

Hi,

I’m using membership 2 with mailchimp add-on.
yesterday I had a blank setting on it.
I downloaded the patch and place it inside wp-content/plugins/membership/app/addon/mailchimp/ and it’s fixed.
But i can’t still add member. When I set the subscription on a new user and save it, it redirect me to :
http://mywebsite.com/wp-admin/admin.php?page=membership2-add-member&user_id=xxx
with a HTTP ERROR 500

Could you help ?
Thanks in advance, Nicolas