If you have two elements whose name only differ by a special symbol (see attached screen shot) it will result in a compile error like this: f:\Dropbox\Support Issues\Client Site - Copy\Pages.g.cs: Line 89: (CS0102) The type 'Client_Site.Pages.IFLFXecutePaymentsSystem20Page.ExpressionDefinitions' already contains a definition for 'TableCell' f:\Dropbox\Support Issues\Client Site - Copy\Pages.g.cs: Line 79: (CS0102) The type 'Client_Site.Pages.IFLFXecutePaymentsSystem20Page' already contains a definition for 'TableCell' Sample project demonstrating the problem is attached. The correct fix may be to NOT record element names with special symbols.