I’ve created custom master page based on Bootstrap framework.
The Open with explorer is working fine in IE10 but It will not working properly in IE11.
Please check the above image
[Route Cause] :
I found that open with explorer button was disabled because of the master page control, the button enable and disable based on the meta tag we used
<meta http-equiv=”X-UA-Compatible” content=”IE=edge”>
I cross check the issue with Seattle master page and Oslo master page in SharePoint 2013.
Based on that, i modified the meta tag like blow
<meta http-equiv=”X-UA-Compatible” content=”IE=10″>
Now it’s working fine in IE10 and IE11, please check below image