Thanks for sharing the console output. You need to change exactly what the output shows.
In the thread you first posted, PLEX_MEDIA_SERVER_TMPDIR was a mistake I had made very early in the development of the Linux packaging support. I had included one variable name which wasn’t supported by Engineering in PMS itself.
The solution for you is to edit /etc/default/plexmediaserver (notice it’s listed as the “Config file used”)
Change that variable from PLEX_MEDIA_SERVER_TMPDIR to be (your choice of) TMPDIR, TEMP, or TMP as the variable name to use.
Now, when you install PMS, it will accept the variable name you’re using in your configuration and show that targeted temporary directory as intended.
