When trying to open up some jpg images obtained from the web into Photoshop, I kept encountering this error: “Could not complete your request because an unknown or invalid JPEG marker type is found”. The images would open in browsers and other applications, but not in Photoshop. It was driving me crazy.
Doing some Google research, I read that changing the extension of the file name to .psd might work, but alas, it didn’t solve the problem, just gave a new error: “Could not complete your request because it is not a valid Photoshop document.”
On a whim, I tried another extension and changed it to .png. And… voila! The image opened up in Photoshop perfectly. Turns out it was actually a png file pretending to be a jpg. Problem solved!
So if you ever come across the ‘Invalid JPEG marker’ roadblock, see if it’s a png in disguise.