DS 216+ works now with 64 bit version… 
You can use the 64bit version fine 
Thanks!! 
You have disabled debug logging. If you are able to get to server settings, please enable debug logging in settings / server / general / show advanced and save changes
Also check that crash reporting is enabled - it is on the same advanced setings server web page
Then restart the server and upload a new zip of the Logs folder
If you are unable to get to server settings, please edit the Preferences.xml file to set logDebug to 1 and sendCrashReports if it is set to 0
See https://support.plex.tv/articles/201105343-advanced-hidden-server-settings/
I believe on Synology the Preferences.xml would be here
/Volume1/Plex/Library/Application Support/Plex Media Server/
Without debug logging - the only possible issue i can gleam is that may be there is DNS or internet connectivity issue with plex.tv
Hi @sa2000
Thanks for your suggestions. However, as of now, with 64 bit version, Plex is up and running.
Thanks
Gopal
Same issue on my DS416play, installing 64 version over the existing installation resolved the issue 
I ran into this same issue with my DS1817+, the link above for Plex version 1.13.4 resolved the issue for me as well.
Thanks a lot. Doing a reset and reinstalling DSM without update2
That definitely fixed it…but why it won’t run 32-bit Plex anymore? I have a DS415+ which has a Intel Atom C2538 processor…which is indeed a 64-bit processor. Maybe Plex will be faster now?
Hi,
same here: installing the x86_64 version PlexMediaServer 1.13.4.5251-2e6e8f841 solved the issue. I guess as the initial installation years ago was 32 bits only, the system just continued to update to the 23 bits version, regardless of the NAS capability.
@treasureChest, Thank you a lot for having pinpointed this !
Can we get some hurrays for @treasureChest !!! 
64Bit version fixed my issues also. Thanks everyone.
Aw shucks everyone I’m blushing, glad I could help!
Thank you @treasureChest, installing the 64bit version solved the issue for me too!
DS1817+ after update to DSM 6.2-23739 Update 2 my Plex PlexMediaServer was failing to start.
But Plex PlexMediaServer-1.13.4.5251-2e6e8f841-x86_64.spk fixed all my problems!
Thanks @treasureChest Getting the 1.13.4.5251 worked for me to 
I also switched to the 64bit version on my DS1815+.
Now its running again.
Thanks to the support.
Had the exact same symptoms on DS1815+. 64 bit solved it. Thanks @treasureChest
Thanks for carrying on while I got some much needed sleep 
So the 32 bit PMS on DSM 6.2 is the root cause of this problem?
That’s definitely a Synology bug but I can work around it by making the installer sensitive to the CPU, DSM version, and package and then refusing to install 32 bits on 64 IF that’s what needs to be done.
Before discussing this further with Engineering, how do all of you feel?
Force 64 bits on a 64 bit machine?
i had 64 bit version (1.12.something) and same issues as the others here.