System.BadImageFormatException occurred when build in Release Mode

Question

I am referencing an exe file in a dll. When run in DEBUG mode everything runs fine but when run in Release mode below exception is thrown

System.BadImageFormatException occurred
  HResult=-2147024885
  Message=Could not load file or assembly 'Presensoft.InlineMarker, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.
  Source=Presensoft.ApplicationServer
  FileName=Presensoft.InlineMarker, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
  FusionLog==== Pre-bind state information ===
LOG: DisplayName = Presensoft.InlineMarker, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
 (Fully-specified)
LOG: Appbase = file:///F:/PresensoftNewTrunk/Trunk/Email Archiver/EmailService/Presensoft.ApplicationServerHost/bin/Release/
LOG: Initial PrivatePath = NULL
Calling assembly : Presensoft.ApplicationServer, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: F:\PresensoftNewTrunk\Trunk\Email Archiver\EmailService\Presensoft.ApplicationServerHost\bin\Release\Presensoft.ApplicationServerHost.vshost.exe.config
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///F:/PresensoftNewTrunk/Trunk/Email Archiver/EmailService/Presensoft.ApplicationServerHost/bin/Release/Presensoft.InlineMarker.DLL.
LOG: Attempting download of new URL file:///F:/PresensoftNewTrunk/Trunk/Email Archiver/EmailService/Presensoft.ApplicationServerHost/bin/Release/Presensoft.InlineMarker/Presensoft.InlineMarker.DLL.
LOG: Attempting download of new URL file:///F:/PresensoftNewTrunk/Trunk/Email Archiver/EmailService/Presensoft.ApplicationServerHost/bin/Release/Presensoft.InlineMarker.EXE.
ERR: Failed to complete setup of assembly (hr = 0x8007000b). Probing terminated.

  StackTrace:
       at Presensoft.ApplicationServer.ExchangeServer2010Push.PostProcessingEmailsQueue()
       at Presensoft.ApplicationServer.ExchangeServer2010Push.RunPushService(Guid appServerID) in f:\PresensoftNewTrunk\Trunk\Email Archiver\EmailService\Presensoft.ApplicationServer\ExchangeServer2010Push.cs:line 48
  InnerException: 

Not sure whether there is some issue with probing exe file when running in RELEASE mode.

Answer 1

More than a Debug/Release mode I'll say it's a 32 vs 64 bits problem. Probably you have the Platform target for the Debug mode to Auto and for the Release mode to 32/64 bits and you are using a dll that is only 32 or 64 bits, so in Debug (Platform target Auto) mode the .NET can "select" between 32 and 64 bits to be compatible with the dll, while in Release (Platform target 32 or 64 bits) it can't.

(note that if you have multiple projects in the same solution you have to check all the projects properties for this! It's in the properties of each project, Build, Platform target)