“An error has occurred with the data fetch. Please refresh the page and retry.”

When trying to open the Site Actions in Firefox the “An error has occurred with the data fetch.  Please refresh the page and retry.” error is displayed.

The Error

When loading any page in SharePoint 2013 using Firefox you get the following error:

Timestamp: 4-1-2013 12:19:34 Error: SecurityError: The operation is insecure. Source File: http://mavention/_layouts/15/core.js?rev=%2FmcwmyWAFSbQRHlXU4BIBg%3D%3D Line: 1

Additionally, when trying to open the Site Actions menu in Firefox, the following error occurs:

An error has occurred with the data fetch.  Please refresh the page and retry.

Similarly you get the same error when trying to open the user’s menu by clicking on the name of the currently logged user.

The Reason and Solution

This error occurs when cookies are disabled in the browser. SharePoint assumes that cookies are enabled and doesn’t explicitly checks for it. What’s worse it doesn’t prompt you about it and throws an error instead.

The only solution to avoid this error is to enable support for cookies in the browser.