Hi,
Unfortunately Combine does NOT support PSD files conversion. But you also mentioned that you are getting the same behavior with JPGs. Can you please provide me the JPG files you used to let me investigate the issue.
Also, can you try combining some other supported files (other than the ones you used) in combine (.jpg, .png , .bmp etc.) , to make sure that its not a generic problem with your installation.
North America
Europe, Middle East and Africa
Asia Pacific