A knowledge base article about Why do I have to log in again? provided by the UC Berkeley IT Service Hub - Knowledge Portal
Here are some reasons you may be asked to log in to CalNet Central Authentication Service (CAS), again:
- Extra security precautions are being taken. Some applications require users to log in regardless of whether or not the user has already done so, although it does defeat the purpose of Single Sign On (SSO).
- The CAS cookie may have expired. CAS uses a cookie to determine if a user has already logged in, and the cookie can expire.
- More than one web browser is open. If you have more than one web browser open, you will need to log in within each browser.
- The CAS session has expired. The CAS session time limit is currently set to 8 hours.
- You have logged out. If you log out of CAS, you will have to log in again.