Web App fails to reach the Plex Media Server

[Daddy21]

Server Version#: DSM 6.2.2-24922 Update 4
Player Version#: 1.21.1.3766

Hello,
The Web App fails to reach the Plex Media Server running on the DSM with the following message:
“The server DataMovie is out of date and cannot be used. This version of Plex Web requires Plex Media Server 1.15.2 or higher.”

As indicated above, the Plex Media Server matches the version requirements.

Is there anything else I am missing ?

After some investigations, I noticed that the Web App redirected unexpectedly to a decommissionned Plex Media Server from a different IP adress. I made some cleanups in the configuration and removed old authorized devices.
However, when I launch the Web Plex from the Synology DSM with the supplied URL, there is no more redirection but the contents of the DSM does not show up anymore.
I tried to follow through the “Your Media” link but it only offers to install another Plex Media Server.
Any hints from anyone?

[Daddy21]

Thank you for your reply. I followed your guidance and installed the DSM version 6.2.3-25426 Update 3 and reinstalled Plex Media Server and it shows as below:

Unfortunately, it leads to no avail.
Should I go for the DSM 7.0 Beta ?

[Daddy21]

I followed the link provided in the Package Center: http://192.168.1.80:32400/web.

[Daddy21]

This is what I get in the browser:

[Daddy21]

Unfortunately, I do not have the item Server>Libraries in the Plex Settings:

[Daddy21]

I restarted the Internet Router and the DSM but I did not see any change. Here attached are the logs.(File removed)

[Daddy21]

Well, I have done something previously since the Server logs were eventually shown.

Attached are the new logs.(File removed) (File removed)

[Daddy21]

Yes I did

[Daddy21]

Solved!
The DNS tips steered me towards the DSM DSN configuration and it happens that the DSN server was stopped. I started it and everything went back to normal.
Thank you very much for your help!