"Input pin x1 of&(9,21) connected to more than one output pin that are not tri state stable"
I get an error like this for each of the pins on the left-most gates in this full adder:
It worked fine independently with button inputs and LED outputs. This error only occurs when I use my full adder as part of a larger adder, such as this one:
Hi,
What you have is a connection between your inputs A and B on the leftmost adder.
In the future you can search for such incidences by selecting all connected wires Hold Shift key and click a wire and using menu Edit – select all different components.
Hope this help,
Eugene