1. An apparatus comprising: a first obtaining unit configured to obtain a physical space image obtained by sensing a physical space by an image sensing device; a second obtaining unit configured to obtain a position and orientation of the image sensing device; a generation unit configured to generate a virtual object based on the position and orientation generated by the generation unit; a synthesizing unit configured to generate a synthesized image by synthesizing the physical space image with the virtual object; a determination unit configured to determine whether an error region exists in the synthesized image; and a display control unit configured to cause a display device to display the synthesized image in a case where the determination unit does not determine that the error region exists in the synthesized image, and to cause the display device to display the physical space image in a case where the determination unit does determine that the error region exists in the synthesized image.