ISO 2293 is from August. When you update it there was probably an upgrade to grub2 that results in this problem. When discovered we told users they could fix the boot-loader fairly easily with this post. We had multiple users report successfully fixing their boot-loader with that article. I encountered this problem and had to fix boot-loader on multiple test systems.
The easiest thing to do would be to use a newer ROME ISO and avoid the problem all together.
Edit: For latest ROME ISOs look here and go to the Main containers:.