The basic problem is :

· User opens form in InfoPath Forms Services

· Changes view

· BOOM – gets an error + correlation id   [Security Validation]

This error was found by Chris O’Connor in our Dev box. So I post here as I need do the same thing to our production servers.

Here is the fix but not a very good option


Fix is as below:

1.       In the 14 hive, under template/layouts, find the formserver.aspx file.

2.       Backup the file and then edit it with any text tool, say, notepad.

3.       Under the <body> tag, add the highlighted line of code.

<body runat="server" id="PageBody">
<SharePoint:FormDigest runat="server" />

4. Save it. Then the problem should be resolved.