RDK wrote:I did nothing to the SD card before running the Update sequence. It is a 16 GB card, which should be plenty large enough.......
NO...... If you installed a standalone image (not NOOBS), then you MUST expand the filesystem before attempting to do any updates or installs.
If not, the default partition will be almost full at installation leaving only ~115MB free regardless of the size of the SD.
If you run out of disk space during an update, the OS will likely get trashed requiring a re image.
Also you need to always do sudo apt-get update (same day), before doing any upgrade or installation.
Expand using the first option in sudo raspi-config or the GUI config utility in [Menu] --> [Preferences]
Unless specified otherwise my response is based on the latest and fully updated Raspbian Buster w/ Desktop OS.