.NET version downgrade generates app.config. Do I need it?

Question

Recently had to downgrade a project from .NET 3.5 to .NET 2.0 because it turns out that the target boxes will not have .NET 3.5 on them.

When I did so (in VS2008), it created an app.config file in each project with this snippet of XML:

<startup><supportedRuntime version="v2.0.50727"/></startup>

• Is this necessary?
• Do I need to ship this app.config (or the resulting XML file) with my app?

Answer 1

It's a good thing to have in there. Your app may run fine without it, so it may not be absolutely necessary, but it gives the runtime more explicit instructions on the target version of the Framework needed. And it doesn't hurt to have in there if it's not needed.

I would keep it.