How Can This Happen

What is wrong with this picture? Normally users can trust that an installer will eliminate previous versions. As you can see in the picture after upgrading to Plex i received a message an upgrade was available. I downloaded it and dropped the .tgz file into the DroboApps folder. When I restarted the Drobo 5N I noticed the info in the attached picture. I did not install this upgrade and did not know how to get the upgrade out. The next time I restarted the Drobo, the downgrade was installed. “Xxxx!”

I guess this is not a search for answers but rather a bit of a notice to other less than expert users, like me.