Resolve exceptions if the service is already defined in the current solution, try building the solution, and then add the service reference again

When adding a native Web service reference "if the service is already defined in the current solution, try to build the solution, and then add the service reference again" exception resolution VS2013 Create an empty project type of "asp.net Web Application", and then want to contact the use of the next webservice. Create a new WebService, the project node right-> add-> Add New Item->web Service (ASMX) WebService. The project node then right--> adds-> service reference, resulting in an error following the download service:
Click on the detailed error, the end of a large series of description: The remote server returned an error: (500) Internal server error. If the service is already defined in the current solution, try to build the solution, and then add the service reference again. However, it is no use to try again by directly adopting its proposal to build a solution.
My modification is to add the following two references to the project. Right-click on the Reference node-> Add Reference find these two namespaces plus OK. Because the default item is not.

Even if you add a namespace reference, you immediately go to add a service reference will find it or not, this time after running the project and then add will be useful.
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