Liferay Vaadin Portlet - JSON Undefined Error in IE

Question

I have a Liferay Vaadin Portlet that is working with no issues (or errors) in both Firefox and Chrome. However, when I use Internet Explorer (Version 11) I get the following error:

Webpage error details
 3
 4User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E)
 5Timestamp: Thu, 6 Nov 2014 17:29:44 UTC
 6
 7
 8Message: 'JSON' is undefined
 9Line: 147
10Char: 8
11Code: 0
12URI: http://server.com/receipt-lookup-portlet/VAADIN/vaadinBootstrap.js

I only get this error when pulling up the page from the server, when I pull it up from my environment I get no errors (using the same browser).

Thanks!

vaadin.version 7.3.4 liferay.version 6.0.6

Answer 1

I believe it may be something do with compatibility mode. Try adding this into your theme:

<meta http-equiv="X-UA-Compatible" content="IE=Edge">

It's possible you've already got something similar, but have used IE conditional comments to condition it's inclusion. IE11 doesn't do IE conditional comments any more so you will need to have the meta tag included for all browsers.