I had the same problem. What fixed it for me was opening it in photoshop and making sure the color mode was set to RGB and not Indexed Color.
Had the same problem when importing .png into Illustrator. Solved it by exporting my file to PNG-24 instead of PNG-8.
In my case same thing happened with Acrobat Pro. It was due to bit-depth. I increased it from 8 to 32 and now it works!
Open the file in Photoshop and resave making sure to turn off interlacing.
Or if turned of then turn on.
From Illustrator at 300 dpi, export to png and check "Use Artboards" that solved the problem for me 🙂