1. An image processing apparatus comprising: a receiving unit configured to receive an activation request for a first application; a determination unit configured to, in a case where the receiving unit receives the activation request when a second application has already been activated, determine whether one of the first and second applications has a predetermined function and other one of the first and second applications is compliant with the predetermined function; a warning unit configured to issue a warning message in accordance with a determination that one of the applications has the predetermined function and other one of the first and second applications is non-compliant with the predetermined function; and a control unit configured to execute an activating process of the first application if an activation instruction is received after the warning message is issued.