- The PNG file really is a PNG file right? Not JPEG renamed to PNG by accident?
- Double check the dimensions -- it is 180x180, right?
- What size is the black icon in your IPA? 0 bytes? Same size as your original file? Some different size?
Kerri, thanks for the excellent suggestions. Unfortunately the .png file really is a .png file that is 180x180 (i have tried creating it in MS Paint and in Adobe Photoshop, with the same results). The resulting AppIcon60x60@3x.png in the .ipa file is also 180x180, so the size is correct, but its content is bad: is just black or maybe just transparent with no content:
After several dozen more experiments I was finally able to create a 180x180px png that was accepted by PGB. I can't say why I finally got one to work, but it definitely was something unusual about the png file and the way the icon (a small map) was being encoded.
Glad you got it working.
Was there perchance some transparency in the prior PNGs?