Old account not working. Created a new one but it’s not working either

[tom80H]

In order to complete the setup you need to open your Plex Media Server through its local IP.
If you’re on the same machine… open http://127.0.0.1:32400/web in your browser. If you’re on a different machine inside your home network, use http://[PMS IP address]:32400/web instead. This will bring up a wizard/dialog where you can name your server and link it to your Plex account (as well as creating your first libraries).

You can also use this new procedure:

@PlexInfo

How do I claim my server?

The process has been simplified. From the Windows system tray (that’s the group of icons shown on the bottom right of the screen ne to the clock), find and click on the Plex Media Server icon. You will be shown a menu of options. Select Open Plex.... (This is not a new option, it was already there.) When the server is unclaimed, this action will now open the default web browser and forward you to Plex.tv to sign into your Plex account. Signing into your Plex account in that browser window will then automatically claim your server and link it to that account.

If your server is not claimed and you explicitly want to not sign in/claim it, cancel this step.

Once you “claimed” your server (=linked it to your Plex Media Account), you’ll also be able to access it from other Plex apps or via http://app.plex.tv/desktop.

https://support.plex.tv/articles/200288586-installation/

No separate accounts are needed to setup a new server.

Sidenote:

@sleazemer

Usually my name would be in top left and I’d click that to add a library only my name isn’t there.

Sounds like your old setup was on a pretty old release of PMS.