You could maybe convert your byte array to a hex encoded string for PrmX ?
Dim bc As ByteConverter
Dim ecbHex As String = bc.HexFromBytes(BytesArray )
sorry, not working as the webservice expects bytes array not string
i don't get error but the parameter does not construct binary element
so when the ws gets it it becomes "garbage"
i can't modify the ws as it is a live one and in use when others are sending bytesarray from pc apps
now i wanted to use it from b4a