ExtJS 4.2: No separator in header of grid in IE11

Description

See screenshot here

Caused By

CSS ‘.x-column-header-inner’ and ‘.x-grid-header-ct’ in ext-theme-classic-all.css cannot display the same in IE11 as in IE8.

Solution

Add ‘background-image: -ms-linear-gradient(top,  #F9F9F9 0%,#E3E4E6 100%)’ to CSS. Remove ‘background-image: none’ from  ‘.x-grid-header-ct’.