www.logiccircuit.org

I built a simple selection circuit with AND, NOT and OR gates in Logic Circuit
and everything worked fine. I then replaced the circuitry with just AND and NOR gates
and LogicalCircuit won't run the circuit. The buttons don't work and the LED does not change
to a darkened colour as it normally does when it has a 0 input.

The project file is attached.

Hi Mario,
What happened is you have 3 unconnected wires on all of your NOR gates that are used as NOT gates. Please note there is no black dots on that wires. See the picture. The optimizer of the program did not find any connections from your buttons to your LED, so it's cut almost everything.
You will need to split each or this vertical wires. You can just select each of them and Alt-Click in the middle.
I also attached fixed version.
Regards,
Eugene

Hi Eugene,

Thanks. I applied the change and the circuit now works.