soap object or property not found with SoapClient php

Question

I have a strange mistake

Fatal error: Uncaught SoapFault exception: [Client] SOAP-ERROR: Encoding: object has no 'BA' property in *** (PATH)

But when I add in object "$RI2->BA = 0;" another error is:

Fatal error: Uncaught SoapFault exception: [SOAP-ENV:Server] mkres: Parameter 'BA' not found in *** (PATH)

What I have to do? thanks for your attension...