Why is ap_vendor_pub_pkg.update_vendor_public returning an error?

I am making a call to the api ap_vendor_pub_pkg.update_vendor_public (as shown in snippet below), the API is returning a status of 'U' unexpected error and no error message, so I don't know what is wrong. I've called this api before in a different program where I was just updating the inactive date and never had an issue. I've checked all the values of the fields, their definitions, lengths, datatypes, etc. and only the end_date_active is NULL. All other values are valid. So, I'm not seeing the reason for this error, any idea what I am missing?