Visual Studio 2010 Mixed Mode .dll fix not working for me...

Question

So I am getting the same exception as a lot of other people when I am trying to run an execute statement into my SQLite database in my Windows Forms project in Visual Studio 2010. The exception reads:

Mixed mode assembly is built against version 'v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.

The exception type is : FileLoadException

Now I found all of the other peoples solutions and changed my app.config to this:

<?xml version="1.0"?>
<configuration>
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
  </startup>
</configuration>

But I save, re-compile, step through the code...same exception.

Do any of you have any idea what this could be?

Answer 1

Yes it is more than just that configuration; there is metadata within the solution so I would change the actual project 'Compile' properties on the .dll or project you are trying to update.

In Solution Explorer within VS.NET, right-click the project and select Properties. From there select the Compile tab on the left-hand side and then press the Advanced Compile Options button. The last dropdown contains 'Target Framework' which you can change to .NET Framework 4.0 if you wish. I recommend to keep all projects within a solution targeting the same framework version, or otherwise the error you encountered will occur. It happened to me to when I converted a project from VS.NET 2008 to 2010, and only 1 of the 3 projects in the solution got upgraded to the .NET Framework 4.0; but this was easy enough to change

Clean and rebuild the solution and then make sure the referencing project does have the new version. This should fix the issue.