There is a problem with upgrading the system-config-printer.
The error is as follows:
[1/23] Extracting system-config-printer-1.5.12_2: 3% pkg: Fail to create temporary file: /usr/local/lib/python3.8/site-packages/cupshelpers-1.0-py3.8.egg-info/.pkgtemp.PKG-INFO.gJdjcIc8ZNWR:Not a directory [1/23] Extracting system-config-printer-1.5.12_2: 100%
It is also a known issue on the FreeBSD project. Here is the FreeBSD Bugzilla ticket https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=264445.
I recommend deleting the system-config-printer and reinstalling it before starting the upgrade. You can reinstall it after the upgrade fails, but the error message in Update Station is not shown due to a bug.
As root, run this command line:
pkg delete system-config-printer ; pkg install system-config-printer
I am sorry for the inconvenience. I will be working on adding code to mitigate these upgrade issues with Update Station So that users don't have to deal with that.