Issue

When trying to access Microsoft 365 applications like Outlook, you receive the following error message:

Error: 403 Forbidden

Cause

The "403 Forbidden" error might occur because of one of the following conditions:

• Your browser cache has to be cleared.
• Your account permissions haven't replicated correctly on the server.

Resolution

Access via Private/Incognito Browsing

First, try accessing the Outlook Web Application (OWA) using your browser's privacy mode.

Based on the browser that you are using, please click on the link below for instructions to enable private browsing.

• Chrome
• Firefox
• Microsoft Edge
• Safari

If you can access Microsoft 365 while you browse in a privacy mode, the issue is with your browser's cache and cookies. Follow the steps in the next section.

If you cannot access Microsoft 365 while you browse in a privacy mode, please contact IT Services or call 773.702.5800 for assistance.

Clear Browser Cache and Cookies

Next, based on the browser that you are using, please click on the link below for instructions to clear your browser cache and cookies.

• Chrome
• Firefox
• Microsoft Edge
• Safari

Access via Normal Method

Finally, attempt to reconnect using your normal method.

If you cannot access Microsoft 365 after browsing in a private session and clearing your cache, please contact IT Services or call 773.702.5800 for further assistance.