clsData is a class that covers a lot of functionality. There are parts that deal with web projects, but cause some troubles when used in other kind of project (WinForms for example). For that reason I use conditional compilation.

This conditional compilation affects to serialization and deserialization because those to features are not used in projects that are not web. For this reason I define a symbol in Project -> Properties -> Build -> Conditional Compilation symbols. The symbol must be defined in all configurations (Debug, Release...).