Update 02/06/2017: Shibboleth is working normally again (the service may be slower than normal for a while following the rebooting of the server).
We regret our authentication system is not working properly this morning. We have reported this to Information Services and advised it requires urgent resolution. We hope that IS will be able to restore normal access very soon. If you are working from home or elsewhere, we recommend using the VPN (or the Web Proxy if this is not possible because you are working from an employers’ computer).
We apologise for the inconvenience.