Sorry - you are not understanding. This is a summary:
- Your PNG file has new features not supported in your 2016 AC3D 8.0
- The latest AC3D 8.6 supports these newer PNG files.
If you want to use that PNG with AC3D 8, you will need to convert the PNG to an older PNG format.
I have converted it for you here:
www.inivis.com/external/marco2.png
If you are determined to not upgrade AC3D, you will need to do this yourself for all PNG files you use.