[Carl Fontaine]

We had the same problem on a project and we finaly found the solution. I’m posting this today because I was searching myself the solution and didn’t found nothing on the web.

The problem is: we had a pre-rendered PNG sequence in our AE project, with some broken file (NOT MISSING). It’s a 2000 frames background playing in loop. We found that some image was rendered (for unknow reason) like this…

You can see the strange lines at the bottom. It’s very hard to see when you’re looking at a big sequence in windows and no image is missing. The PNGIO error come up in AE only when you are on that image, in the project. That’s how we found which exact frame was broken.

Also, we are rendering on a renderfarm. Maybe the PNG sequence had error because of this…

We re-rendered the broken PNG, restarted the render, and now it’s fine!

I hope that help!