Windows: "Key not valid for use in specified state" error and transcoding/analysis issues

When running Plex Media Server on a Windows computer (and particularly if you've upgraded from a much older version of the server), it's possible you might encounter transcoder-related issues. This might manifest in multiple ways, but some common symptoms include:

  • Content can Direct Play, but fails when any type of transcoding is needed
  • Media analysis fails and you don't see media format information on item details/preplay screens

Verifying the Issue

You can verify whether this particular error is causing your issue by examining your Plex Media Server logs. Affected users will have a log line similar to the following:

Jul 23, 2016 03:41:35.686 [10716] ERROR - Unexpected error configuring transcoder: boost::filesystem::unique_path: Key not valid for use in specified state

After reproducing the issue, look inside your Plex Media Server.log or Plex Media Scanner Analysis.log files and then search for "Key not valid for use in specified state". If you see a log line similar to above with that text, then you're affected by this issue.

If you're not sure what to look for or where, post details in our support forums and be sure to attach your full set of Plex Media Server logs.

Related Page: Plex Media Server Log Files
Related Page: Plex Forums

Resolving the Issue

The following steps will resolve the issue for the vast majority users.

  1. Stop/exit your Plex Media Server so it isn't running
  2. In Windows Explorer, rename or move the following directory: %APPDATA%\Microsoft\Crypto\RSA
  3. Start Plex Media Server

That should cause the cryptographic cache information to be re-built automatically.