I have a Visual Studio 2010 Windows Forms app which includes a Form base class that other classes will inherit. The base class\' constructor takes a parameter that the child
You need to adjust your BaseForm output type, In the properties for the project, change the Output type from Windows Application to Class Library.
ref: https://docs.microsoft.com/en-us/dotnet/framework/winforms/advanced/walkthrough-demonstrating-visual-inheritance