as mentioned in this post: Windows 10 Desktop App Synced Content Requires Internet Connection
I had previously used the Plex MacOS app and downloaded content while online, and apparently an update downloaded in the background. I quit the app, only to relaunch it when I was in airplane mode on a flight, and saw an “updating” dialog, and the app updated itself. after this, I couldn’t play any of my downloaded content, it errored saying there were missing codecs. I had to pay for wifi so the codecs could download.
When plex ships updates, it shouldn’t install them when offline due to this issue, or it should bundle the codecs with the updates!
