P: Can't open PNG files

Yup. That's the issue. PSD saved with PNG extension. Preview opens it as PSD using the embedded preview.

Doesn't look like it kept the whole comment... anyway accidentally tried to open the file and it griped about a font (red flag) so I changed the extension to PSD and it opened as a layered PSD

was 6mb... did you see my whole diatribe on what I found or just the 1 and a half line comment it kept?

How big is the file?

which explains why preview could see the image...

OK more interesting... went to post one of the "bad" png files, as requested, but it was too big (s what hung us up...

Can you post one of the affected files?

James, Suddenly our whole shop has the same problem with PNG's as well... created by PS saved as PNG (non-interlaced)... won't read it back in. No altering of file extension or anything... preview sees it just fine. PSD won't recognize it, nor will Epson's Garment Creator. Did you have any luck yet?

Sorry, I should have mentioned that I've been doing this for 17 years. I didn't add a wrong file extension or anything of that nature. It's a png. Also, it is repeatable. If the file is corrupted, it would appear to be Photoshop that corrupted it, because I created the file in Photoshop. Strange that Photoshop would corrupt a file in such a way that Photoshop can't read it, but other software can.

Most likely you used the wrong file extension on the file (like putting PNG on the end of a JPEG file filename), but it is also possible that something in the file is corrupted (part that Preview doesn't read).