If you are using SSO and Safari and receive the message, "Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.”,  this usually means a cookie or header (often a cookie) has grown too large for the web server to process. Here’s how you can fix it:

Clear Cookies for the Affected Site Only

1. In Safari, go to Safari > Settings > Privacy > Manage Website Data.
2. In the search box, type gsu.edu
3. Select it and click Remove ALL.
4. Reload the site.

This fixes the issue in most cases because it removes bloated cookies that exceed header size limits.