Category: Shibboleth

FOLLOWING RECENT SECURITY enhancements to the configuration of NTU’s Single Sign On environment (which enables staff and students to log in to online resources using their university username and password), library customers are more likely to occasionally encounter a ‘stale request’ error.

This error can occur for a number of reasons, but its most frequent cause is that some of the session information stored in the user’s web browser has timed out, and is therefore no longer acceptable to the SSO system. The most effective and reliable solution to the problem is to clear the cache on the requesting browser and then sign in afresh.

The ‘stale request’ error has been generating regular service queries for library teams from staff and students, who are understandably unsure what the error means or how to resolve it.

The ‘out of the box’ error response in the SSO system provides no next-step guidance.

Working with colleagues in Digital Technologies, the library has now been able to arrange the deployment of a customised error response in the SSO environment, which returns a more meaningful message and which includes links to online guidance on cache clearing and further support. (As the SSO system supports authenticated access to a wide range of university applications and systems, it’s appropriate for the main Service Desk to triage any service calls which might arise.)

The new response message will appear in the browser as in the screenshot below:

The text of the new response message is as follows:

Authentication error: please clear your browser cache!

A technical problem has occurred which is causing your login request to this resource to be rejected.

To ensure that you’re able to authenticate successfully, you’ll first need to clear the sign-in data cached by your browser before trying again to access this resource.

The Digital Technologies team at Nottingham Trent University provide an up-to-date walkthrough which explains how to clear the cache of all the most popular browsers. Follow the simple steps in the How to clear your Cache on iPad, PC and Mac guide.

If the problem persists after clearing your cache, please contact support@ntu.ac.uk, with details of your device, browser and the resource you are trying to access.