Sophos Policy Evaluation Service not starting Service cannot be started. Could not load file or assembly 'log4net, Version=1.2.14.0

HI All I have this error

Any ideas?

Service cannot be started. System.BadImageFormatException: Could not load file or assembly 'log4net, Version=1.2.14.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a' or one of its dependencies. The module was expected to contain an assembly manifest.
File name: 'log4net, Version=1.2.14.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a'
at Sophos.PolicyEvaluation.Service.PETService.OnStart(String[] args)
at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)

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].