I encountered an identical issue when burning it from Windows. I was able to fix it by switching to a new flash drive and reburning the image. So, I think in my case it was a failing flash drive, a corrupted image, or both.

I burned mine from a Windows machine but got the same error. I fixed it by doing a reboot, but encountered more errors later in the installation process. I finally fixed it by switching to another flash drive. I suspect the one I was originally using might have had a corrupted image, or been going bad.