This Program is AWFUL!!! First I could not figure out how to switch circuits, or whatever those ting things are, and then, I got this big error message that says: Input pin x1 of Symbol of Gate: And on LogicalCircut: Sub-Adder(18, 12) connected to more than one output pin that are not tri state compatible. What is THAT supposed to mean!?! How can you possibly expect ANYONE to understand that?!?!? Therefore I think this program is AWFUL.
As for error message yes I agree it is a bit cryptic. If you can suggest a better one I’d be happy to change it in the future version. But for now it means that you have connected two different outputs to one input. The rest of the words means which input of which circuits has improperly connected, so you track down the erroneous place and fix it.
Hope this will help.