With the release of Internet Explorer 9, our CMS experience went downhill in a hurry. The CMS screens render horribly. Thankfully, Microsoft envisioned problems such as these and engineered a solution that can be applied to the server.

Internet Explorer Rendering Modes

Versions 8 and 9 of Internet Explorer have shipped with the rendering engine of previous versions built in. By default, IE will look at for the existence of a DOCTYPE to trigger it to render in standards or quirks mode. However, it also supports standards mode rendering for each prior version back to IE7. The trick is specifying which version you want.

Custom Headers

Internet explorer looks for the X-UA-Compatible http header in order to determine what rendering mode it should use. In the absence of that header, it will either render in standards mode for the newest browser if there is a DOCTYPE, or use quirks mode (roughly IE5) rendering.

For OpenText (RedDot) CMS, the appropriate value is “IE=EmulateIE8”.

Learn more about the X-UA-Compatible header

Configure IIS

It’s a simple matter to add custom headers in IIS. You can find the option in the IIS Snap-in, under the properties for the CMS folder.

And that’s all there is to it. Your editors should now see the site as rendered by IE8.