[SOLUTION] I found that this button was disabled because of this line in my Master Page – I am using Bootstrap theme from Codeplex and that comes with its own master page. What I had to do was change this line in the header from: to (taken from Seattle master page) And now, the button is enabled …
![SOLVED: “Open with explorer” disabled in IE11](https://usercontent.one/wp/sharepointbabe.com/wp-content/uploads/2015/03/openexp.png)