SGEN failure: An attempt was made to load an assembly with an incorrect format in VS2008
format, mixed-mode, sgen, visual-studio-2008, web-reference
Solution
Have you tried changing `Generate serialization assembly` to `Off`, as suggested in this msdn post? In my case, that was the ticket.
Just go to your Project properties, and it's under Build.
Problem
I was able to find several similar questions asked and answered, but none of the answers or exact conditions applied to my situation. - I have a .NET 3.5 project being built for x64. - I also have an x64 mixed mode reference (also targeting .NET 3.5). - In Visual Studio 2008, I created a Web Reference which causes SGEN to execute during a Release build to create the helper DLL. If I don't reference the `mixed-mode DLL`, this works fine. If I do reference the mixed mode DLL, I get this error (xxx is just a placeholder): SGEN : error : An attempt was made to load an assembly with an incorrect format: C:\code\xxx\trunk\xxx\common\xxx\build\winx64\lib\xxx.dll. This is the command being issued: C:\Program Files\Microsoft SDKs\Windows\v6.0A\bin\sgen.exe /assembly:C:\code\xxx\trunk\xxx\xxx\obj\x64\Release\xxx.dll /proxytypes /reference:..\common\xxx\build\winx64\lib\xxx.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.configuration.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Configuration.Install.dll /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\System.Core.dll" /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.EnterpriseServices.dll /reference:C:\Windows\assembly\GAC_MSIL\System.Management.Automation\1.0.0.0__31bf3856ad364e35\System.Management.Automation.dll /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.0\System.Runtime.Serialization.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.0\System.ServiceModel.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\System.Web.Extensions.dll" /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Web.Services.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll Any ideas?