title: OpenLayers webapplication stopped working in IE11
body: <p>A few years ago we developed an OpenLayers webapplication.
  Everything worked fine until a few weeks ago.
  The application stopped working in IE11, became very slow in Edge.
  No problems with other browsers.
  When I try to debug (by pressing F12) IE crashes.
  The application is used by a few hundred users, a lot of them use IE.</p>
  
  <p>The application loads a big WFS-file.
  During 5 to 10 minutes IE "does not respond".
  After that period IE is back and alive, and the application works normally.
  This behaviour started a few weeks ago.</p>
  
  <p>I have made a Q&amp;D testaccount and link: <a href="http://62.212.154.154/geluidregister/inloggen?u=test123&amp;w=test123" rel="nofollow noreferrer">http://62.212.154.154/geluidregister/inloggen?u=test123&amp;w=test123</a>
  As soon as you load the page IE will hang for a few minutes.
  If you press F12 during that period IE will crash.
  After those "few minutes" you can use IE normally.
  This behaviour started a few weeks ago.
  Edge is also 'suffering' but doesn't crash.
  Other browsers have no problems.</p>
  
  <p>Settings:</p>
  
  <ul>
  <li>Internet Explorer: Version 11.674.15063.0 Update version 11.0.47
  (KB4040685) </li>
  <li>Installed KB's since september: 
  KB4051613 
  KB4049179<br>
  KB4041676
  KB4040724 KB4038788 KB4038806  </li>
  <li>IE security zone: Protected Mode enabled (translated from Dutch)</li>
  <li>As far as I know there is no Emulation mode (at least I didn't change
  any settings in that area)</li>
  </ul>
  
  <p>Tests/checks:</p>
  
  <ul>
  <li>Delete cookies and browser history - no results</li>
  <li>Reset IE setting - no results</li>
  <li>Run in 'compatibility mode' - no results</li>
  <li>Test in 'no-Addons mode' - no results</li>
  <li>Event error after IE crashes (only when I press F12):</li>
  </ul>
  
  <blockquote>
  <pre><code>- &lt;Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"&gt;
  - &lt;System&gt;
    &lt;Provider Name="Application Error" /&gt; 
    &lt;EventID Qualifiers="0"&gt;1000&lt;/EventID&gt; 
    &lt;Level&gt;2&lt;/Level&gt; 
    &lt;Task&gt;100&lt;/Task&gt; 
    &lt;Keywords&gt;0x80000000000000&lt;/Keywords&gt; 
    &lt;TimeCreated SystemTime="2017-11-14T08:20:56.300741300Z" /&gt; 
    &lt;EventRecordID&gt;20949&lt;/EventRecordID&gt; 
    &lt;Channel&gt;Application&lt;/Channel&gt; 
    &lt;Computer&gt;COMPUTER57&lt;/Computer&gt; 
    &lt;Security /&gt; 
    &lt;/System&gt;
  - &lt;EventData&gt;
    &lt;Data&gt;IEXPLORE.EXE&lt;/Data&gt; 
    &lt;Data&gt;11.0.15063.608&lt;/Data&gt; 
    &lt;Data&gt;324c3bf4&lt;/Data&gt; 
    &lt;Data&gt;MSHTML.dll&lt;/Data&gt; 
    &lt;Data&gt;11.0.15063.674&lt;/Data&gt; 
    &lt;Data&gt;5d4c0b6f&lt;/Data&gt; 
    &lt;Data&gt;c00000fd&lt;/Data&gt; 
    &lt;Data&gt;004e9e0f&lt;/Data&gt; 
    &lt;Data&gt;37b4&lt;/Data&gt; 
    &lt;Data&gt;01d35d210863f55d&lt;/Data&gt; 
    &lt;Data&gt;C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE&lt;/Data&gt; 
    &lt;Data&gt;C:\WINDOWS\SYSTEM32\MSHTML.dll&lt;/Data&gt; 
    &lt;Data&gt;61f7af7b-f2fc-43e6-98d5-7ee291007ec8&lt;/Data&gt; 
    &lt;Data /&gt; 
    &lt;Data /&gt; 
    &lt;/EventData&gt;
    &lt;/Event&gt;
  </code></pre>
  </blockquote>
  
  <p>Debugging:</p>
  
  <p>I've tried the following (thanks to IECustomizer Rob):</p>
  
  <ul>
  <li>Open blank page</li>
  <li><p>Apply setting</p>
  
  <p>"Always record developer console messages"</p></li>
  <li><p>Press F12 and apply settings:</p>
  
  <p>"Network recording ON"</p>
  
  <p>"Break on ALL exceptions"</p></li>
  <li>Go to problem website with the dev tool open</li>
  </ul>
  
  <p>But still IE crashes.</p>
  
  <p>Could it be a recent IE/Edge update that's creating this problem?.</p>
  
  <p>Any suggestions?</p>
  
  <p>Regards,
  Koen</p>