I tried the system recommended 'dpkg --force-remove-reinstreq' command and got an error message that it didn't recognize the command. I tried a number of variations on the format, but nothing worked. I switched to 'aptitude', read the manual and eventually was successful in updating the system. When I first opened 'aptitude' it recognized there was a problem with the status and said to run 'dpkg --configure -a', which I did. when I reopened 'aptitude' it opened without the error. After reading the manual I decided to run 'aptitude safe-upgrade' from the command line. This worked! It took a while to work its way through the packages that were not up to date (73) and held (34), but eventually it finished. The updater now says the system is "up to date". Hurrah.