C# Error Message: .NET 2.0 DLL in .NET 4.0 cannot be loaded in the 4.0 runtime without additional configuration information

Your DLL is a CLR 2.0 mixed mode assembly. To use these, you need to add to your app.config file of your project the line <startup useLegacyV2RuntimeActivationPolicy="true" />, so that your app.config looks like this, for example:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <startup>
    <startup useLegacyV2RuntimeActivationPolicy="true" />    
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0,Profile=Client" />
  </startup>
</configuration>

Thereby you are telling the CLR, which version it should use to load your DLL. However, this does not apply to managed assemblies. So, a CLR 2.0 managed assembly can be loaded even without this line.
Last update on 2021-06-13 | Created on 2012-12-27

I have added these lines in app.config but its not working. I am using sqlite dll with visual studio 2010.
2013-06-12 at 07:22

Hello,

I have already changed in App.Config file like this

<?xml version="1.0"?>
<configuration>
<startup useLegacyV2RuntimeActivationPolicy="true">

<supportedruntime version="v4.0" 
            sku=".NETFramework,Version=v4.0"/>
</startup>
</configuration>

and target framework also changed. But I got an exception while i was executing the database script with ExecuteNonQuery method.

"system io fileloadexception mixed mode is built 
against version 2.0"

Any Idea about the problem?

Thanks in advance.
2014-03-10 at 13:24