Creating a record in zoho CRM Custom Module - 4401 error

Creating a record in zoho CRM Custom Module - 4401 error

I'm trying to create a record in a Zoho CRM custom module. Code was working perfectly but all of a sudden stopped. I've stripped the code down to basics and still get an error.

  2.     equipMap = map();
  3.     equipMap.put("CustomModule2 Name", "test");
  4.     resp = zoho.crm.create("CustomModule2", equipMap);

This code is run onClick. I get the following error each time:
{"message":"Unable to populate data, please check if mandatory value is entered correctly","code",4401"}

The CRM mandatory value is "CustomModue2 Name" which is entered. I don't have any "mandatory" fields in the stateless form. 

Appreciate any help