A route named ‘*’ is already in the route collection, Azure Web App

I was deploying an ASP.NET Web API to an Azure App Service Web App and I got this error:

Server Error in ‘/’ Application.

A route named ‘HelpPage_Default’ is already in the route collection. Route names must be unique.
Parameter name: name
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentException: A route named ‘HelpPage_Default’ is already in the route collection. Route names must be unique.
Parameter name: name

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

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Figure 1, A route named ‘HelpPage_Default’ is already in the route collection. Route names must be unique.

I resolved this with the next deployment of my Azure App Service Web App by clicking the “Remove additional files at destination” checkbox and the Publish.  See Figure 2.

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Figure 2, A route named ‘HelpPage_Default’ is already in the route collection. Route names must be unique.  Remove additional files at destination

Then it worked out as expected.