The Chat Plugin is not being displayed in IE9 using without Developer Tool. If I open Developer Tool and refresh the page, it shows up.
I tested it through Browserstack.
Someone posted the same issue here: https://premium.wpmudev.org/forums/topic/internet-explorer-problem#post-448944
And Paul created a site:
I checked that site out and didn't show up in IE9 until you open Developer Tool and refresh the page.
I've the most recent WordPress (3.9.1) installed and Chat Plugin (22.214.171.124) as well. I've changed the theme. Still no changes.
And there are no JS errors in console.