Well luckily on Debbie and base systems you have the good old tried and true dpkg or apt. 

"The software on this computer is up to date."   Success!   Thank you for your input. I ran the commands I found in the Google search, I wanted some human input before I did any of them. I don't know what would have interrupted any previous updates. A few days ago (after I made my return post) I got an error about unmet dependencies and a suggestion to check them in Synaptic. However, Synaptic didn't show any issues, and the error just went away. I don't know what caused that, but after a system lock up a couple weeks ago, I started feeling uneasy. I've been running Xubuntu on an old laptop for years with little issue, and a year ago after a bad Windows update, I ditched it for Xubuntu on my main system here and until recently it's been flawless.  

I am running Xubuntu.   I tried apt install -f and it returns similar errors as before:   E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.    Running dpkg --configure -a returns the error mentioned in my original post:  dpkg: error: parsing file '/var/lib/dpkg/updates/0000' near line 0:  newline in field name '�v��'   So I can try that sequence of commands that came up in searches. I understand what they are doing, I just wanted to verify that is a good course of action.

Agreed Hedon

What distro you running?  Obviously Debian based, but would be helpful if you mentioned in the future.   You seem to have an update that was interrupted & never completed.  I would start with the dpkg command, run from the terminal, to see what is happening behind the GUI.  Then I would run sudo apt install -f to "force" missing packages.  Then try to update again.   If still no success, run the commands specified, in the order specified.  You have a corrupted update (from partial update) and need to either "force" it forward (my recommendations), or remove the corrupted partial update (Google recommendations) and try again.