Whats new to this update is the addition of the line
to torrc. In addition there is a new user “tor” and group “tor” added, and the ownership of the folder /var/lib/tor is changed to the new user “tor”.
Here comes the problem: If you have made changes to your torrc, the config file is not automatically updated. Instead a new torrc is created with the new defaults (added the User setting). As your config is not changed, but the ownership of /usr/lib/tor is changed, the service will fail to start because it checks that the folder is owned by the user the service will run as.
If you follow the advice above; to rename the new torrc, and add whatever custom config you had in your old torrc to the new, you’ll still get a very similar error. Because all files and subfolders under /usr/lib/tor is only writable by root. To solve this:
# chown -R tor:tor /usr/lib/tor
The automatic update script seems to have forgotten the -R.