Ubuntu 16.04 installation failed "did not match source copy"

Question

I went through all the steps to install Ubuntu dualboot with Windows 10 on my Lenovo T430 laptop. I got as far as allocating drive space between Windows 10 and Ubuntu. After I hit continue the installation immediately failed and a dialogue window popped up with the following message:

Installation failed

The following file did not match its source copy on the CD/DVD:

/target/usr/bin/snapctl

This is often due to a faulty CD/DVD disk or drive, or a faulty hard disk. It may help to clean the CD/DVD, to burn the CD/DVD at a lower speed, to clean the CD/DVD drive lens, to check whether the hard disk is old and in need of a replacement, or to move the system to a cooler environment.

It then gives me three options: abort, retry and skip. None of these work and I can't close the dialogue window either. Im just wondering what to do next and if its safe to just restart the computer.

I am trying to install Ubuntu 16.04.

Answer 1

As the error message states (emphasis mine):

Installation failed

The following file did not match its source copy on the CD/DVD:

/target/usr/bin/snapctl

This is often due to a faulty CD/DVD disk or drive, or a faulty hard disk. It may help to clean the CD/DVD, to burn the CD/DVD at a lower speed, to clean the CD/DVD drive lens, to check whether the hard disk is old and in need of a replacement, or to move the system to a cooler environment.

The first thing you should check is that the ISO you used to burn the CD/USB with is not corrupt. Look at How can I check the integrity of a downloaded Ubuntu CD.

If that is fine, then remake the CD/USB. The burn/image may not have completed successfully.

If that is not the problem and you are using a CD, then the high likely hood is that the CD is scratched or dirty. Examine the CD. If there is dust on it, wipe it off with a cloth. If there are scratches, use a different CD.

If you have tried everything above and you are using a USB, then the USB is probably broken. You may like to try to repair it if it is a costly USB, but that is out of the scope of this question. Reimage the ISO onto a different USB.