Plex Server Certificate Rejected by Android and Plex Remote Access Checker

Plex Media Server Remote Access
,
1

Plex Media Server Logs_2026-07-22_21-25-00.zip (3.2 MB)

plex-log-2026-07-22T20_27_20.521Z.zip (29.5 KB)

Plex Server Certificate Rejected by Android and Plex Remote Access Checker

Server Version#: 1.43.3.10828
Server OS: macOS 15.7.7
Server Hardware: Mac Studio, Apple M2 Max
Player: Plex for Android Mobile
Player Version#: 2026.13.0 (971050317)
Android Version: 16

Problem

My Plex Media Server is accessible through Plex Web on the Mac, but the Plex Android app cannot reliably find or connect to my libraries, either on the local Wi-Fi network or through mobile data.

The server is using a manually forwarded TCP port:

External 32400 → 192.168.0.15:32400

The Remote Access page reports that the server is fully accessible outside my network. Incoming Android and Plex reachability-check connections reach Plex Media Server, but fail during the TLS handshake.

Plex Media Server repeatedly loads:

  • Certificate UUID: 35f17f3841f047aeae9e42aeff8440ee

  • Certificate fingerprint: 76:29:65:ab:98:59:8a:ac:bd:08:13:15:5b:2f:4d:ef:d8:43:cc:38

Relevant log entries from 22 July 2026 include:

[CERT] Installed certificate with fingerprint 76:29:65:ab:98:59:8a:ac:bd:08:13:15:5b:2f:4d:ef:d8:43:cc:38.

SSL certificate problem: unable to get local issuer certificate

CERT: incomplete TLS handshake ... tlsv1 alert unknown ca

CERT: incomplete TLS handshake ... sslv3 alert certificate unknown

The sslv3 alert certificate unknown entries appear immediately when the Android app attempts to connect. A separate Plex external reachability checker also reports tlsv1 alert unknown ca.

Steps to reproduce

  1. Start Plex Media Server.

  2. Open Settings → Remote Access.

  3. Select Manually specify public port 32400 and click Apply.

  4. Open the Plex Android app on mobile data.

  5. The server libraries are not found.

  6. Plex Media Server logs a failed TLS handshake from the Android connection.

Troubleshooting already performed

  • Confirmed TCP port forwarding from public port 32400 to 192.168.0.15:32400.

  • Confirmed incoming Android connections reach Plex Media Server.

  • Restarted Plex Media Server and the Android app.

  • Searched the user Library for cert-v2.p12; no file exists.

  • Stopped Plex Media Server and removed only CertificateUUID and CertificateVersion from com.plexapp.plexmediaserver.plist.

  • Restarted Plex Media Server.

  • Plex restored the same Certificate UUID and loaded the same certificate fingerprint.

  • The unknown ca, unable to get local issuer certificate and certificate unknown errors remain.

Could Plex staff please reset or reissue the plex.direct certificate or secure-connection registration associated with this server?

I have attached:

  • A fresh Plex Media Server logs ZIP covering a restart and failed Android connection.

  • The Plex Android mobile logs ZIP covering the same connection attempt.

2

Stop plex, go to the folder in the path below and remove the certificate from the folder, *.p12 (Your cert may not be named cert-v2.p12, it may just be certificate.p12), and restart plex so that it pulls down a new certificate. If that doesn’t fix it, may need someone from plex to refresh it on their end.

/Users/<username>/Library/Caches/PlexMediaServer

Screenshot 2026-07-12 at 4.10.58 PM

If you don’t see that Library folder in your user directory, show hidden files/folders by pressing Command + Shift + “.” .

4

Thank you veeejay for taking the time to answer. And actually, I think you’ve hit the nail on the head! I had been doing what you suggested but had been trying to find and delete the ‘cert-v2.p12’ file.

The proper fix was to delete the ‘certificate.p12’ not the ‘cert-v2.p12’ file. On deleting the file you suggested, a new ‘cert-v2.p12’ file was generated with an updated fingerprint which seems to work. I can now start my android Plex client and now it seems to reliably locate my libraries!

Thank you so much!

5

Glad that got you back up and running! :folded_hands:t4:

6

I’m experiencing the same certificate issue on Plex Media Server for macOS, version 1.43.3.10828. Remote Access briefly turns green and then becomes unavailable. Port 32400 is correctly forwarded and verified externally as open. My WAN IP matches my public IP, so there is no double NAT.

The server logs repeatedly show tlsv1 alert unknown ca, certificate unknown, SSL_ERROR_SYSCALL, and Mapped - Not Published. A search of my entire user Library confirms that cert-v2.p12 is missing. Could a Plex staff member please reset/revoke the certificate associated with my server so PMS can obtain a fresh one? I have the complete server logs available.

7

You may not have that certificate version, look in the path noted for “certificate.p12”.