Sonarr/Sonarr · warning · PlexVersionException

Found version {0}, upgrade to PMS 1.3.1 to fix library updat

Error message

Found version {0}, upgrade to PMS 1.3.1 to fix library updating and then restart Sonarr

What it means

Thrown by PlexServerService.ValidateVersion when the detected PMS version is in the range [1.3.0, 1.3.1). PMS 1.3.0 had a bug that broke library updating, so Sonarr refuses to proceed and asks the user to upgrade to 1.3.1 or later and restart Sonarr. It is a PlexVersionException (subclass of PlexException).

Source

Thrown at src/NzbDrone.Core/Notifications/Plex/Server/PlexServerService.cs:84

            catch (Exception ex)
            {
                _logger.Warn(ex, "Failed to Update Plex host: " + settings.Host);
                throw;
            }
        }

        private List<PlexSection> GetSections(PlexServerSettings settings)
        {
            _logger.Debug("Getting sections from Plex host: {0}", settings.Host);

            return _plexServerProxy.GetTvSections(settings).ToList();
        }

        private void ValidateVersion(Version version)
        {
            if (version >= new Version(1, 3, 0) && version < new Version(1, 3, 1))
            {
                throw new PlexVersionException("Found version {0}, upgrade to PMS 1.3.1 to fix library updating and then restart Sonarr", version);
            }
        }

        private Version GetVersion(PlexServerSettings settings)
        {
            _logger.Debug("Getting version from Plex host: {0}", settings.Host);

            var rawVersion = _plexServerProxy.Version(settings);
            var version = new Version(Regex.Match(rawVersion, @"^(\d+[.-]){4}").Value.Trim('.', '-'));

            return version;
        }

        private void UpdateSections(Series series, List<PlexSection> sections, PlexServerSettings settings)
        {
            var rootFolderPath = _rootFolderService.GetBestRootFolderPath(series.Path);
            var seriesRelativePath = rootFolderPath.GetRelativePath(series.Path);

View on GitHub (pinned to da2284d7ea)

Solutions

Upgrade Plex Media Server to 1.3.1 or newer (current stable preferred), then restart Sonarr.
If on a NAS, update the PMS package via the NAS package manager.
Confirm the upgrade took effect by re-checking the version reported in PMS settings.
Restart Sonarr after upgrading so the version check re-runs against the new PMS.

Defensive patterns

Strategy: validation

Validate before calling

// Compare the parsed PMS version against the known-bad range before acting.
var badLow = new Version(1, 3, 0);
var badHigh = new Version(1, 3, 1);
if (version >= badLow && version < badHigh)
{
    // Warn the user to upgrade; optionally disable library updates.
}

Type guard

bool IsKnownBadVersion(Version v) => v >= new Version(1, 3, 0) && v < new Version(1, 3, 1);

Try / catch

try
{
    ValidateVersion(version);
}
catch (PlexVersionException ex)
{
    logger.Warn(ex, "PMS version {0} has a known library-update bug; upgrade required.", version);
    NotifyUserUpgradeRequired();
}

Prevention

Keep PMS on a current stable release.
Surface version warnings in the UI proactively after a Test.
Pin NAS PMS packages to a known-good version if auto-update is unreliable.
Restart Sonarr after upgrading PMS so version checks re-run.

When it happens

Trigger: GetVersion returns a version whose major.minor.build is 1.3.0. The version is parsed from the PMS /version endpoint via regex taking the first four dotted/hyphenated numeric groups.

Common situations: Old PMS install pinned to 1.3.0; nas distribution shipping an outdated PMS package; a test/staging PMS not kept current.

Related errors

AI-assisted analysis of Sonarr/Sonarr@da2284d7ea (2026-08-13). Data as JSON: /api/errors/79c8bf7f510e3e55. Report an issue: GitHub.