When logging into T4, some users have reported the following error appearing:

There are three usual causes of this:

  1. You have not completed training on T4 - If you have not completed training on T4 version 8 then your account will be set as disabled. Once you have completed training you will be granted access.

    If you have not already done so, fill in this form to request training on terminalfour (T4) Site Manager.

  2. There is an issue with the cookies on your browser - this is the most common cause of this error. You will need to clear the cache of your web browser completely to resolve this - see instructions below on how to do this in Google Chrome and Firefox.

  3. You are not using the correct URL to log in to T4 - please ensure you always log in using https://t4-cms.imperial.ac.uk

Step 1 - First make sure you are using the correct URL

Make you are trying to log in at the correct URL: https://t4-cms.imperial.ac.uk

Step 2 - Clear your browser cache

Please note that clearing your cache only partially (such as for the last 24 hours) will not solve it. It is important to clear your cache completely by selecting 'All time' or 'Everything', depending on your browser. The options you select should look like this -

Google Chrome






Step 3 - try an incognito browser tab

Clearing the cache resolves the 401 issue for most users. If it doesn't work, you can try using an incognito browser tab. Instructions on how to do this are linked below:

Step 4 - try a different web browser from your normal one

If you normally use Chrome, for instance, try Firefox or another different web browser to see if the issue persists. Links to download other browsers are below:

I'm still getting a 401 error when logging into T4

Please try all of the steps above to resolve the issue - if you have tried all options and are still experiencing the error, please email your Faculty Web Officer: