I have a very large and complex web application running .NET 3.5, with some classic ASP pages and VBScript components thrown in for good measure. The site is running on IIS7, and is a root website.
Ideally, I'd like to have a sub-application beneath this website which runs .NET 4, to deploy new components. However, this is presenting me with difficulties and the following error is showing:
The value for the 'compilerVersion' attribute in the provider options must be 'v4.0' or later if you are compiling for version 4.0 or later of the .NET Framework. To compile this Web application for version 3.5 or earlier of the .NET Framework, remove the 'targetFramework' attribute from the element of the Web.config file.
Is this going to be possible at all, or should I give up and find another way?