ie explorer have some question

[ch1035063420]

My app works perfectly in all other browsers but breaks in IE8-10 . The error from the debugger is:

SCRIPT5007: Unable to get property 'headercontainer-1026-drag-status-proxy' of undefined or null referenceext-all.js (12785,17)

copyright is Ext JS 4.2

Here's my code Could anyone please suggest what is the issue?

QQ图片20170909085418.png
QQ图片20170909085403.jpg

[Gary Schlosberg]

I'm not able to determine the issue from that error. Are you able to recreate this issue in a runnable test case?
https://fiddle.sencha.com/#view/editor

[ch1035063420]

hi:
I created a test case https://fiddle.sencha.com/#view/editor&fiddle/26fb