CRM API w/ Self Client (Administrator): You do not have sufficient permission to associate this record. Contact your administrator.

CRM API w/ Self Client (Administrator): You do not have sufficient permission to associate this record. Contact your administrator.

I am using the CRM API and am having an issue creating a contact.  I've successfully created a contact linking to an existing account by ID, but then when I created a separate test account (which succeeded) and tried to create a contact linked to that separate test account, the operation failed.  

The response body was: {"data":[{"code":"INVALID_DATA","details":{"api_name":"id","json_path":"$.data[0].Account_Name.id"},"message":"You do not have sufficient permission to associate this record. Contact your administrator.","status":"error"}]}

I am the administrator.  I can authenticate, refresh tokens, retrieve everything, and the scope on my Self Client is ZohoCRM.modules.ALL,ZohoCRM.settings.ALL

What am I missing?