I have a 9.5.0 issue in visual studio. I get:
When I delete the core.dll reference in Web, the error disappears. As soon as I do a build, it "magically" reappears.
This started happening after I cloned shoppingcart.aspx, ShoppingCartControl.cs and ShoppingCartLineItemDescriptionControl.cs. All the public properties/methods were renamed and do not conflict.
I'm not sure where to look next.
Thanks - Abbott