An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)

Hi 

I'm getting the error when i try to expose custom service using the WSDL URI.

The error seems something like im trying to execute 32-bit  type application in 64-bit or vice versa. Even i tried setting application property "Enable 32 bit-application" as true, though the error still persists 

https://blogs.msdn.microsoft.com/axsupport/2014/12/12/error-when-browsing-a-custom-service-hosted-as-iis-web-service-an-attempt-was-made-to-load-a-program-with-an-incorrect-format-exception-from-hresult-0x8007000b/

Followed the link and did checked the contract objects and its members with respective attributes.