HTTP Error 404.3 - Not Found
The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.
My problem was that WCF wasn’t enabled in the IIS server. To fix this, I ran the following commands in an administrator command prompt.
C:\> DISM /Online /Enable-Feature /FeatureName:WCF-HTTP-Activation C:\> DISM /Online /Enable-Feature /FeatureName:WCF-HTTP-Activation45