Writing a custom function and I'm trying to create a record in a custom module. Here is relevant code snippet:

objectfields = Map();

objectfields.put("Agent",agentID);

objectfields.put("Client",clientID);

resp = zoho.crm.create("CustomModule1",objectfields);

info resp;

It's returning:

{"code":"INVALID_MODULE","details":{},"message":"the module name given seems to be invalid","status":"error"}

But, obviously the module name isn't invalid. So what is the problem??