SOLVED: Log help request. (could not start jellyfin......)

[DLK]

Need to learn to figure out what log is telling me. (Also fixing the issue).

Trying to help someone else with their JellyFin setup and get some education along the way. 

What I know thus far:

Windows 10 machine (he's building a dedicated server a little along that will likely be TrueNas, so go easy on us here).
Jellyfin 10.10.7

System power supply died (was during shutdown, not running... found on attempted system on).
Replaced PSU and Jellyfin would start. 

Here's where there may be an issue. He closed JellyFin and reinstalled it. 

Log as follows:

[2025-11-09 19:01:01.798 -06:00] [FTL] [1] : Failed to create/read logger configuration
System.IO.FileNotFoundException: Could not load file or assembly 'Serilog.Expressions, Version=5.0.0.0, Culture=neutral, PublicKeyToken=24c2f752a8e58a10'. The system cannot find the file specified.
File name: 'Serilog.Expressions, Version=5.0.0.0, Culture=neutral, PublicKeyToken=24c2f752a8e58a10'
  at System.Reflection.RuntimeAssembly.InternalLoad(AssemblyName assemblyName, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext, RuntimeAssembly requestingAssembly, Boolean throwOnFileNotFound)
  at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
  at Serilog.Settings.Configuration.ConfigurationReader.LoadConfigurationAssemblies(IConfiguration section, AssemblyFinder assemblyFinder)
  at Serilog.Settings.Configuration.ConfigurationReader..ctor(IConfiguration configSection, AssemblyFinder assemblyFinder, ConfigurationReaderOptions readerOptions, IConfiguration configuration)
  at Serilog.ConfigurationLoggerConfigurationExtensions.GetConfigurationReader(IConfiguration configuration, ConfigurationReaderOptions readerOptions, DependencyContext dependencyContext)
  at Serilog.ConfigurationLoggerConfigurationExtensions.Configuration(LoggerSettingsConfiguration settingConfiguration, IConfiguration configuration, ConfigurationReaderOptions readerOptions)
  at Jellyfin.Server.Helpers.StartupHelpers.InitializeLoggingFramework(IConfiguration configuration, IApplicationPaths appPaths)

[theguymadmax]

That looks like there may be something wrong with the logging config file?
logging.default.json which is in the config folder. 


this is the default config:

Code:

{
    "Serilog": {
        "MinimumLevel": {
            "Default": "Information",
            "Override": {
                "Microsoft": "Warning",
                "System": "Warning"
            }
        },
        "WriteTo": [
            {
                "Name": "Console",
                "Args": {
                    "outputTemplate": "[{Timestamp:HH:mm:ss}] [{Level:u3}] [{ThreadId}] {SourceContext}: {Message:lj}{NewLine}{Exception}"
                }
            },
            {
                "Name": "Async",
                "Args": {
                    "configure": [
                        {
                            "Name": "File",
                            "Args": {
                                "path": "%JELLYFIN_LOG_DIR%//log_.log",
                                "rollingInterval": "Day",
                                "retainedFileCountLimit": 3,
                                "rollOnFileSizeLimit": true,
                                "fileSizeLimitBytes": 100000000,
                                "outputTemplate": "[{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz}] [{Level:u3}] [{ThreadId}] {SourceContext}: {Message}{NewLine}{Exception}"
                            }
                        }
                    ]
                }
            }
        ],
        "Enrich": [ "FromLogContext", "WithThreadId" ]
    }
}

[DLK]

EDIT>>>>>>>>>> STRANGE ONE BUT RESOLVED>>

Looked for 0mb data files and found only one. jellyfinlog was 0. delted it and restarted......

Now, how a log file could cause such issues, I don't know. It's working though!




Well, that led to something of an answer. Summery and further question.

He reinstalled 10.10,7

Noticed in his DL folder jellyfin 10.11.0

Looks like either he or someone updated recently.

Tried installing from the newer .exe and same issue.
Downloaded and installed 10.11.2 and is now working.
However, can't install plugins. Add repository and restart to no joy (on or off of VPN).
Under "Plugins" is the default 6.
There is no "My Plugins" or "Catalog" were these removed or is this another symptom related to current concern.
About to go gen new log.