Tienes una instalación incorrecta
ERROR> 2024-02-28T11:57:03 MCEBuddy.Engine.Core --> MCEBuddy Monitor Thread Crashed. Error: System.IO.FileNotFoundException: Could not load file or assembly 'ObjectDumping, Version=1.0.0.0, Culture=neutral, PublicKeyToken=5b84c0cf1ad6e363' or one of its dependencies. The system cannot find the file specified.
File name: 'ObjectDumping, Version=1.0.0.0, Culture=neutral, PublicKeyToken=5b84c0cf1ad6e363'
at MCEBuddy.Engine.Core.WriteJobHistory(ConversionJob job)
at MCEBuddy.Engine.Core.MonitorEngineThread()
WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
Esto ocurre si intentas actualizar desde una versión anterior a 2.6.3 directamente sin desinstalar primero la versión antigua: MCEBuddy Monitor Thread Crashed after first item is processed in the queue v2.6.2 - #4 by Goose
Desinstala y reinstala MCEBuddy y debería funcionar correctamente.