IE11 partially crashes

Question

I’m running an older website for Internet Explorer, using VBScript and an ActiveX object (RAPI, C++) developed by our team. Since IE11 does not support VBScript we use the emulate tag,
<add
name="X-UA-Compatible"
value="IE=EmulateIE9"
/>,
 in the config file. We also use iFrames (not displaying cross domain web pages).
This setup works fine in IE 8, 9, 10 but not in IE11. The problem is that after our ActiveX component has displayed a modal dialogue IE crashes. It’s not closed down or restarted but it gets these symptoms:
Drop down lists doesn't expand. They are populated  and you can scroll all values using the arrow keys but it will not expand.
You cannot start Developer Tools after this point. (F12)
You cannot open internet settings.
View source is opened in notepad instead of the built in viewer.
You cannot leave the website by typing www microsoft com (or any other address) in the address field. You can still go to other pages in our own site but not leave our site.
After this crash it’s still possible to use our web site with full functionality, except for the drop down lists. The symptoms in the list above remains as long as the tab is open.
Anyone with similar experience?
Thanks
Andreas

Answer 1

Hi Andreas,
try
Tools>Internet Options>Advanced tab, check "Always record developer console messages",
uncheck "Disable script debugging other"
Save changes...
open a blank tab in IE (about:blank), then
f12>Debug tab, select "Break on all exceptions", then
go back to the blank tab and navigate to your intranet site.
dismiss any exceptions in the debug tab of f12, that are trivial and allow the site to load...
select the console tab to display any xss or blocked resource warnings.
select the emulation tab and check that your site has loaded with IE9 emulation... (it will tell you how the emulation was established, expected x-ua meta tag)
(possibly the workstation that you are testing on may have "display intranet sites in compatibility view" checked and the site first displays in IE7 emulation, or another mode if enterprise mode is deployed).
also check that it is mapped to the expected IE Security zone (File>Properties menu). expected intranet. Ensure that the Allow scripting of ActiveX controls is allowed in that zone.... (for a test you may like to turn on 'prompt' on the Security zone
options.)
mmm....(I'm not sure about this)... you should be able to locate vbscript block that calls your AX methods and place a break point on it.
back in the browser invoke the AX method call (by clicking a button?)
f12>Debug tab should break, at which stage you can step through the client script, up to the point of the method call.
BUT probably the best way to debug the issue is from Visual Studio.
(the client method above should display a message asking you if you want to debug any byte code errors using Visual studio)
Rob^_^