c# - Mailchimp.Net api code is giving exception when adding interest group -

c# - Mailchimp.Net api code is giving exception when adding interest group -

i using mailchimp.net in asp.net c# web application.

i trying add together involvement grouping using next code:

mailchimp.mailchimpmanager mailchimpmanager = new mailchimp.mailchimpmanager("xxxxxxxxxxxx-us9"); if (session["listid"] != null) { string listid = session["listid"].tostring(); list<interestgrouping.innergroup> innergroup = new list<interestgrouping.innergroup>(); innergroup.add(new interestgrouping.innergroup() { name = "students", bit = 1, displayorder = 1, subscribers = 0 }); mailchimpmanager.addlistinterestgrouping(listid, this.textboxnewgroup.text, "radio", innergroup); }

but addlistinterestgrouping method giving next exception:

mailchimp.errors.mailchimpapiexception: backend database error has occurred. please seek 1 time again later or study issue.

internal excpetion is:

the remote server returned error: (500) internal server error.

i not getting why issue occurring, other methods of api working. has faced before or study author ? please help.

c# asp.net mailchimp