ajax tabcontainer not rendering tabs in IE8

Question

I'm using ajax tabcontainer within updatepanel ( and i have placed toolscriptmanager in master pages) to render 2 tab controls. The tabs are rendering in Firefox but throwing error in IE8

ERROR:
0x800a01b6 - Microsoft JScript runtime error: Object doesn't support this property or method

It throws above error at below line of code in ScriptResource.axd file

self._tabIndex = opt.owner.get_tabs().length;

I'm using VS 2013 framework 4.5 and AjaxControlToolkit.dll 4.5.7.1213

Please help in getting this fixed.

Thanks

Answer 1

I used AjaxControlToolkit dll available @ http://www.kartris.com/uploads/General/AjaxControlToolkit_fixed_for_ASP.NET_4.0.zip which fixed my issue

Answer 2

Above trick helped me and it's really working after trying out all different options. I'm not sure if this is a recommended way though and how to upgrade to newer versions if the problem still persists.