System locked up during upgrade 18.04 to 20.04

[REUBY Dianne]

> On 30 September 2020 at 23:02 Liam Proven <lproven at gmail.com> wrote:
> 
> 
> On Wed, 30 Sep 2020 at 20:20, REUBY Dianne via ubuntu-users
> <ubuntu-users at lists.ubuntu.com> wrote:
> >
> > What should I do now?
> 
> Boot from an Ubuntu USB key and check your root partition with the
> `fsck` command.
> 
> Then reboot from the hard disk.
> 
> [1] try to complete the upgrade:
> 
> sudo -s
> apt update
> apt full-upgrade -y
> 
> [2]
> 
> If this complains that there are broken packages, try:
> 
> apt install -f
> 
> then retry step #1.
> 
> Let us know what happens.
> 
I wasn't quick enough with the function key to boot from my USB, so booted from hard disk. I got a message telling me I needed to complete an upgrade, which ran very quickly. No instruction to restart though. 

Everything appears normal. Thanks for your help.
Dianne