Code://Ext.util.CSS.refreshCache(); Ext.util.CSS.getRule(".x-body");TypeError: rules is null
Code:getRule: function(selector, refreshCache, rawCache) { var i; if (refreshCache) { CSS.refreshCache(); } if (!Ext.isArray(selector)) { return rawCache ? rules[selector.toLowerCase()] : rules[selector.toLowerCase()].cssRule; } for (i = 0; i < selector.length; i++) { if (rules[selector[i]]) { return rawCache ? rules[selector[i].toLowerCase()] : rules[selector[i].toLowerCase()].cssRule; } } return null; },