See these two documents:
- Installation & Setup of Plex Media Server on Synology
- Synology FAQ - Questions, Answers, and How-To’s
If you wish to bring over your database, etc from the PC, see FAQ 26 - Migrate from another OS → DSM 7.
When using the claim token, did you see the “successfully claimed by …” message, to indicate the process was successful?
Is the new server displayed in your list of Authorized Devices?
Using a private/incognito browser window, connect directly to the IP address of the NAS.
For example, if the IP address is 10.1.2.3, use http://10.1.2.3:32400/web.
- Use http.
- Don’t forget /web.
- For the initial login, do not use the “open” button in Package Center, Synology Quick Connect, a FQDN, etc.
- The private browser window is to bypass any plug-ins that might get in the way.
If the claiming process was successful, you should be able to login and access server settings.