To clarify: you can see sailfish in multirom when you boot the device, but it reboots to recovery when you select it?

edit: the only change in this zip is system.jar. Even if system.jar was bad, sailfish should still boot. This seems like it could be a recovery issue.

Did you see the flashing message afterward?

Edit2: What twrp version are you on? I can't recreate the issue using the twrp linked in topic, and "sfdroid-hammerhead-cm121-prealpha2.zip"

Edit3: Also try re-downloading the zip if possible.