Image is coming up as 'invalid image file'
I have created a number of images in photoshop and have saved them as jpegs. Justinmind will let me put some but not all into prototype and for the ones it won't, 'invalid image file' keeps coming up. I've changed settings in images, played around with the size and everything but nothing is fixing it. Please help!! It's for an MA assignment and needs to be complete within two weeks!