Harold -
Thanks for your response and thoughts. It is the TINA simulator that I am concerned about, not my circuit configuration.
When I simplified my circuit down to the essentials to make my point, I thought, you know plenty of people are going to take me for an idiot making a circuit like this, but I hope some will get the point that I am asking about the behavior of TINA, not my dumb wiring. What is shown as the center ground is actually an Arduino pin that changes from an Input pin to a ground pin. But I can't get TINA to work in even this simplest of configurations.
If I breadboard what is shown in the jpeg, there is no problem. But TINA chokes. I was hoping someone familiar with it would say "oh, that is because of this and that. all you have to do to successfully model it is change such and such".
And maybe you are right about the net thing. But where is part 2 ? What is the such & such that I should change ? Just kidding Harold. I do appreciate your taking the time to try and help me.
p.s. the door switch is not completely irrelevant TO MY QUESTION because it is the act of closing it that generates the "Irregular Circuit" error message.