linqdatasource - can't find a reference for LinqDataSource used in designer

Question

When converting a website to a web app, the designer creates the code

protected global::System.Web.UI.WebControls.LinqDataSource

and I get the error

namespace name 'LinqDataSource' does not exist in the namespace 'System.Web.UI.WebControls'

when I try to compile.

Answer 1

I tried creating a new project, making sure LinqDataSource was working by adding it from the toolbox to a webpage.

After copying my existing project into the solution as a folder it failed, turns out it doesn't like the bin folder from my previous project in a subfolder of the new project.