Been working with Claude all day through this before I came to the board. After showing it my post plus your response and then giving it the background that I had tried making an completely new un-associated account and still had the problem it suggest a fix. In summary this is everything we did in case it helps someone in the future. I really appreciate the help and the thoughtful response. It seems to have gotten us over the line.
Setup: New machine running fresh Windows 11. Plex Media Server, Sonarr, Radarr, Jackett, qBittorrent, FlareSolverr all installed and working. An external exFAT drive (D:) holds the media library, previously used with Plex on an old Windows PC.
Initial symptom: Clicking “Add Library” in Plex Web always returned to a screen saying “Add your media to Plex — download Plex Media Server,” even though Plex Media Server was confirmed installed and running locally:
- Confirmed process running in Task Manager
- Confirmed listening on port 32400 via:
netstat -ano | findstr 32400
First round of troubleshooting (did not fix it):
- Tried direct local URLs:
http://127.0.0.1:32400/web/index.html, ?forceLocal=1, /web/index.html#!/setup
- Tried
/claim endpoint manually:
Invoke-WebRequest -Uri "http://127.0.0.1:32400/claim" -UseBasicParsing
Returned 403 Forbidden.
- Got a claim token from
https://www.plex.tv/claim/ and tried:
Invoke-WebRequest -Uri "http://127.0.0.1:32400/myplex/claim?token=claim-XXXXXXXXXXXX" -UseBasicParsing
Returned 404 Not Found (this endpoint doesn’t exist on the installed server version, 1.43.2.10687).
- Fully uninstalled Plex via Windows Settings, deleted
%LocalAppData%\Plex Media Server, cleared browser cookies, reinstalled fresh. Exact same symptom persisted.
- Created a brand new Plex account, completely unassociated with any prior account. Exact same symptom persisted even with the new account. This was the key data point that ruled out a simple account-permissions issue.
The clue that redirected the investigation:
At this point I posted on the Plex forums. A Plex employee asked whether I was accessing Plex Web via local IP or the system tray, and noted that my account showed a server with a name starting with “E” that had been seen online recently. That server was from the old PC — at one point during testing I had reconnected the old PC and its drive and briefly run Plex on it again, which republished that old server to my account.
I also mentioned I had, at an earlier stage, followed Plex’s official “Move an Install to Another System” support article, which involves copying the entire Plex Media Server AppData data directory (and on Windows, registry keys) from the old machine to the new one, intending to preserve metadata/watch history. The combination of these two facts (old server still known to the account + AppData/registry copied over) was the working theory.
Diagnosis command (the important one):
Invoke-WebRequest -Uri "http://127.0.0.1:32400/identity" -UseBasicParsing
This endpoint requires no authentication and just reports server identity. It returned:
claimed="1"
machineIdentifier="5c222c21bf94357756df308c9e83e3078688990b"
The fact that it showed claimed="1" — even when testing with a brand-new, never-used account — indicated the locally running server already believed it belonged to an account (almost certainly carried over from the copied AppData/registry data), so no new account could claim it, and Plex Web’s “Add Library” UI degrades to the generic “download Plex Media Server” prompt when it can’t resolve a claimable server.
The actual fix:
Stop-Process -Name "Plex Media Server" -Force -ErrorAction SilentlyContinue
Stop-Process -Name "PlexService" -Force -ErrorAction SilentlyContinue
Then uninstalled Plex Media Server via Windows Settings → Apps.
Then deleted the AppData data directory completely:
Remove-Item "C:\Users\<username>\AppData\Local\Plex Media Server" -Recurse -Force
Then deleted the Windows registry key completely:
Remove-Item "HKCU:\Software\Plex, Inc." -Recurse -Force
Reinstalled Plex Media Server fresh (downloaded directly from plex.tv, no data copied over this time).
Verified the identity again:
Invoke-WebRequest -Uri "http://127.0.0.1:32400/identity" -UseBasicParsing
This returned a different machineIdentifier (7b173e30b41a09d6bdf099c910da007dedaa33e5), confirming a genuinely fresh, unclaimed server instance — but it still showed claimed="1" immediately, which was unexpected for a brand-new install.
The final piece:
At that point I checked the browser tab being used for setup and discovered it had been signed out of the Plex account at some point during testing (likely from one of the account-switching steps earlier). Signing back into Plex in that browser tab immediately triggered the proper “set up your server” flow instead of the generic “download Plex Media Server” screen, and the library setup wizard then worked normally.
Root cause, in full:
A stale/orphaned server claim, left over from copying the Plex AppData and registry data from the old machine per Plex’s own official migration instructions, prevented the new server install from being claimable by any account, including a brand-new one — manifesting as a generic “download Plex Media Server” prompt instead of a clear “this server is already claimed” error. This was compounded by, and partially masked by, the browser also being signed out of Plex at the time of testing, which produces the exact same generic UI symptom on its own. Both factors needed to be resolved (full data/registry wipe + reinstall, and being properly signed in) before the real setup flow appeared.
