A server connected to an image processing device over a network, executes: running an application that operates in cooperation with the image processing device; obtaining screen information to use the application from the application based on a request from an external device; outputting the screen information to the external device; detecting an error on the image processing device with which the application operates in cooperation; and adding error information to access an error screen constructed by the image processing device to the screen information when the error on the image processing device is detected. The server outputs the screen information with added the error information to the external device when the error information is added to the screen information.