The DS415play is a 32 bit Intel CPU.
To get this all to work, you will need to “migrate” your metadata from DSM 6 → DSM 7.
There are some details which have to be done for it all to work – and it will take time because each file (metadata) will be converted and moved.
(Yes, this is a royal pain but that’s what happened to us in DSM 7)
Look here
Scroll down.
You will probably want to start at “Scenario 2”
Of all the steps in there where you give “PlexMediaServer” Full Control of the Plex shared folder,
The most important step is to remember to check the box “Apply to this folder, sub-folders and files” as you grant the permissions.
Without it, it will fail
When it starts to work… It will sit there.
Don’t interrupt it or navigate away from the page
Open a new tab to DSM, look in the Plex share, and you’ll see a “Migration.log” file after about 3 minutes.
You can follow the progress.
It’s done when you see “Cleaning /volume1/Plex” completed.
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After all I’ve written here, if it finishes very quickly
AND
your metadata is still in the Plex shared folder. let me know
It’ll mean we need to clear things out and then do it again/