"POST /{user_id}/businesses" to create a business portfolio,

"error": { "message": "Invalid parameter", "type": "OAuthException", "code": 100, "error_subcode": 1752189, "is_transient": false, "error_user_title": "No business email address", "error_user_msg": "This user does not have a valid email address. Please enter a valid email address in the Email address field.", }

The error message will look something like this.

Setting an email address for the target Facebook account or adding an email parameter to the Post request does not help.