When I boot my system, I am greeted with the following message:
kernel panic - not syncing: no working init found. Try passing init= option to kernel
I have tried multiple times to launch Ubuntu but it won't work even when I boot recovery mode. Right now I can't use Ubuntu at all and I have very valuable documents on Ubuntu.
The simplest first step is to recover the files via a live CD.
You can follow this link for more detailed information: Recovering user files with a Live CD
The second harder step is to fix the system that is causing you problems. for that you need to provide more info on you operating system such as Nade, Version, special set-ups, etc.
I remember having the same problem with live+persistence USB of Ubuntu 16.04. I wasn't able to boot it the second time and it was showing the same thing as you mentioned in the question. I clearly remember it was due to what I chose after booting for first time in the
Software and Updates
Additional Drivers
The above mentioned was my personal experience. It may or may not apply to you. Sincere advice would be to recover your files with any live usb before you try and fix anything. Better safe than sorry.
Regardless, you can check out this answers for the same problem.
