1. An image processing device comprising: a storage unit configured to store a plurality of applications, each of the plurality of applications being associated with attribute information; an instruction reception unit configured to receive an instruction for activating a first application of the plurality of applications stored in the storage unit; an activation unit configured to activate the first application of the plurality of applications; a determination unit configured to, if the instruction reception unit receives an instruction for activating the first application of the plurality of applications in a state where the activation unit has already activated a second application of the plurality of applications, determine whether function information included in attribute information associated with the first application is included in attribute information associated with the second application, the function information indicating a function required by the first application to the second application; and a control unit configured to restrict activation of the first application by the activation unit in response to the determination unit determining that the function information included in the attribute information associated with the first application is included in the attribute information associated with the second application.