You’ll need to upload/install that file on the ReadyNAS… not your PC.
We just had a similar discussion in a different thread:
By the way: PMS 1.11.3 is super old (it was released almost 3 years ago)… updating will take a moment as Plex needs to forward-migrate and update your database to catch up with the changes from – so give it some time when you start it for the first time after the update.
