Local Plex Media Server Will Not Allow Login

Went to open my Plex server (running on CentOS 7) and saw that there was only one user listed: me.  Seemed odd since I have several users on that installation.  Clicked the drop-down by my avatar and noticed I appeared to be signed out.  “No problem, I’ll just sign in.”
Except I couldn’t.  Upon clicking to login I was presented with a page stating:

“Plex is not reachable.
Make sure your server has an internet connection and any firewalls or other programs are set to allow access.”

After some brief internet searching, including the Plex forums, found the apparently tried-and-true solution of deleting two bundle directories.
However, these instructions were not accurate in my case.  They list the directory containing these bundles as being:

$PLEX_HOME/Library/Application Support/Plex Media Server/Plug-ins/

Where $PLEX_HOME is /var/lib/plexmediaserver.  In my case, I ended up finding the directories in:

/usr/lib/plexmediaserver/Resources/Plug-ins-4613ce077

So here’s what I did:

systemctl stop plexmediaserver
cd /usr/lib/plexmediaserver/Resources/Plug-ins-4613ce077
rm -rfv System.bundle
rm -rfv Framework.bundle
systemctl start plexmediaserver

And all was well again.