How Can I add new app.Config file?

I'm trying to use 开发者_StackOverflow社区SQLite in my .Net application but it throws an exception and I get this

Additional information: 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.

From here I read the solution that's is changing app.config file, but in my solution folder there is no configuration file, where is that configuration file? what should I change? thanks

You can add your own app.config file to your project. Right click the project and add new items. Then add the lines that was given in the other link.