Please be sure you logged into Client Portal from the IBKR webpage as opposed to accessing it from TWS. If you are unable to complete a request in Client Portal, first clear your cache and cookies on your browser. If the issue persists, please try using a different web browser than the one you used initially.
If the issue remains after testing different browsers, please contact IBKR Client Services. Please select Technical Assistance as the ticket category followed by Client Portal.