Adding values to Multi-Select Picklist

Adding values to Multi-Select Picklist

I'm trying to take values from a multi-select picklist in CRM, and populate a multi-select picklist in Desk, through a custom function.  

I'm able to get the values of the CRM field and am putting them into a list (maybe this is a bad way of doing it) called reasonsList, then am trying the following:

mp1 = Map();
mp2 = Map();

mp2.put("cf_reasons_for_hold", reasonsList);
mp1.put("cf",mp2);

updateTicket = zoho.desk.update(OrgId, "tickets", ticket_id, mp1);
info updateTicket;

this is the response I get:
{"errorCode":"INVALID_DATA","message":"The data is invalid due to validation restrictions","errors":[{"fieldName":"cf_reasons_for_hold","errorType":"invalid","errorMessage"