Symptoms:
Provided that WorldServer is configured via proxy, the buttons for saving a Search filter and for deleting Search criteria are not visible within the Search panel of the Projects page.
Resolution:
You can fix this issue by deploying the update to WorldServer 10.4.5, available on FTP.
If you cannot deploy it, connect to the Customer Support Web Portal and log a case. You need an account to log a case. If you do not have an account, contact your company's SDL Support Account Administrator.