org.ksoap2.serialization.SoapPrimitive cannot be cast to org.ksoap2.serialization.SoapObject

org.ksoap2.serialization.SoapPrimitive cannot be cast to org.ksoap2.serialization.SoapObject

This  exceptions is generally due to invalid returned value from a method.

you have on your code:

SoapObject   soapObject = (SoapObject) envelope.getResponse();

you must correct it by using bodyIn not getResponse().

your code must be like this:

SoapObject   soapObject = (SoapObject) envelope.bodyIn ;