ds212j plex package not found

Until the last dsm 6.1.3 update i’m not able to find the plex package and i cannot use my plex pass in the best way with my nas.
What is the problem?

The DS212J is a single processor ARMv5 . Plex discontinued support for all ARMv5 and PPC systems some 18 months ago.
DS212j Marvell Kirkwood 88F6281 Single Core 1 No 88f628x DDR3 256 MB

:confused: So i need to change the nas to be able to use plex again?

You can always run PMS on your computer and allow the NAS to provide your media storage / file serving functions but it cannot run PMS anymore.

Is there the possibility to run an older version of the pms.
I need a cheap solution to run pms and keep it online like my synology.

No,

Run PMS on your computer and let the DiskStation be the NAS it is