When running the Web application, you encounter the "Failed to download *.* file" error.
Cause: The file extension is not added to the MIME type list in IIS.
Solution: Set up the MIME type for the file name extension that cannot be downloaded.
Step 1: Open IIS Manager. Select the Web site hosting the Web application.
Step 2: In Features View, double-click MIME Types, then in the Actions pane, click Add, and then in the Add MIME Type dialog box, type the file name extension in the File name extension text box, for example, type .config, and type a MIME type in the MIME type text box, for example, text/xml, and click OK.
Step 3: In Features View, double-click Request Filtering, and then remove the file name extension (for example, .config) from the list.