Error updating WCF service reference in silverlight project

Question

I an working on a website build in silverlight that use wcf services to communicate with business layer.
Previously i am working on windows xp, 32 bit system. Few days earlier i am migrated to win 7, 64 bit system along with same project.

I able to run the project with some changes in IIS. But now i change a service method parameters and i want these changes to be reflected in silverlight project but i am getting error while updating the service.

I tried to remove the reference so that on adding reference again, conflict will be resolved but same error shown on adding the reference.
Below is the snapshot of the error message.

As you can see i am running the visual studio with administrator role so i got the full read/write permissions.
Meanwhile i check the option of "View in Browser" for that service, and it shows no error, service is fine.

Answer 1

Had the same problem, the reason turned out to be: One of the object from the server side that was returned to the client had a parameter added to its constructor which meant it no longer had a default constructor.

It wasn't until someone had to change a service method and update the references that we hit the error, which was weeks after the constructor change was done. I was sent down the road of the mismatch bindings and lost a lot of time before figuring that one out!