I recently saved an image on Photoshop CS6 as a PNG file so I could send it as an attachment to a client (who uses a Windows computer). They told me the file wouldn't open and instead showed as an "Unknown File".
I tried opening the file on my Windows computer, as well as a JPEG version to test out, but both came up as "Unknown Files".
The only way I could transfer the files I saved in Photoshop was to export them as PNG through the 'Preview' application.
Is there a reason why these normal formats won't open properly?