Unable to Update

[stevef]

Can you try changing the Ubuntu repository ?

Menu
Settings
Scroll down to 'Software & Sources' and click on it
Ubuntu Tab - note the current  'Download from:' location and then click the pull down against it.
Select another source, e.g. 'Main Server' and enter your password when asked
Close the window, accepting the refresh confirmation.

In a terminal do 'sudo apt clean'

Try updates again.