When the Content-type is application/json under IE9, IE10, and IE11, a download pop-up box will appear when opening the interface.

Solution: Set the Content-type in the header to text/json;

For example, PHP: header("Content-type: text/json;charset=utf-8");

The above has introduced that when the Content-type is application/json under IE9, IE10, and IE11, a download pop-up box will appear when opening the interface, including relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.