It dawned on me after posting this that not only did I update the system, but when the update finished, Rigo showed that there were files that needed to be edited or altered. Not sure which files, but I've always just accepted whatever seems to be the option to automatically accept or update the files. That's what I did after the latest update, and that may be what's causing this problem.
I can get to a terminal by rebooting to the advanced option, and signing in as root. I just tried updating using "equo update," and I get a message saying that "Invalid file system encoding ANSI_X3.4-1968, must be UTF-8. Make sure to set LC_ALL, LANG, LANGUAGE to valid UTF-8 values. Please execute: LC_ALL=en_US.UTF-8 /usr/bin/equo-update"
After doing that and trying again to update equo, I received a similar message, this time for /user/bin/equo install entropy rigo.
Not sure where to go from here, and not sure if this helps pinpoint my problem or just adds muddle to the mix, but it's what I've done so far.