The words written in the front
IIS has set directory browsing enabled, and files can be accessed normally, which indicates that these settings are OK. However, when you click the file to download, you will be prompted that the file cannot be downloaded, the file does not exist, and so on. Some are OK. After one operation, it is found that the file type is not included in the mime.
Open IIS to find the MIME type
Site > Default Web site > webname
After entering the MIME type, click add on the right to add the extension and type of your file
Type can refer to extension type of existing MIME type