Upfrading from Ubuntu 14.03 to Ubuntu 16.0

[Peter]

On the first machine I have tried to complete the upgrade I followed all 
the advice but the machine will not let me access the encrypted area. No 
matter what i enter for the pass word it will not progress past this.The 
second machine is still at the terminal prompt before any attempt to 
make it continue. I can see all of my user data files. Is there any way 
to back them up to an external disk before I continue?If not then I will 
lose about a month of work which is easily redone.

I have an up to date backup on the first machine.  I am not certain if I 
used two partitions in the original installation.  How can I find this out?
I will probably have to reinstall ubuntu 14 on both machines. How do I 
set up two partitions, one for Ubuntu and one for user files? Should I 
continue to use encryption on the drive?

I am grateful for all the help so far.  .


Regards


Peter Goggin