Error:” The security validation for this page is invalid.” – SharePoint 2007

Recently one of our customers had a strange issue in their SharePoint 2007 environment and thought of writing a post. The error was “The security validation for this page is invalid. Click Back in your Web browser, refresh the page, and try your operation again.”

This occurred when a user tries to add a link to their “My Links”. This is a custom master page and I thought something wrong was with the code, but I couldn’t find any issues with the code. This was working fine sometime back. So I dug deeper and found out that the version was the issue.

At the time the SharePoint 2007 version was 12.0.0.6562 (MOSS 2007 or WSS 3.0 June 2011 Cumulative Update). So we deployed a new test SharePoint 2007 server with service pack 2 and we couldn’t recreate the issue. Then we updated the server with the above mentioned CU and finally the error appeared.

The solution is to update the server with the service pack 3 (new version 12.0.0.6608). This may be fixed by a CU, more recent than the June 2011 CU. But we managed to fix by installing the Service pack 3.