Nice screenshots are worth thousands of words.
I have a Cerberus firmware 4.3.6.0.
Plugging 5 or 6 give me the same exception.
The display is show black screen, as if it was not powered.
The exception looks like it is from InitializeModules() (in program.generated.cs),
but it looks like you are also initializing the module in ProgramStarted() (in Program.cs)
Are you sure you aren’t trying to initialize it in two places? (one from the generated code from the designer, and one manually in Program.cs) ?
What does your "InitializeModules() function look like?
@ Nicolas Dorier - Do you have the N18 connected in the Gadgeteer designer?