Hardware Simulator showing strange error message and not loading my CPU chip

[thedumbone]

seems like my CPU chip has some bugs but the error message is not helping. it says "line 100, ainstruction has no source pin". First of all, I don't understand what does it mean and second, my code does have exactly 100 lines but that includes LOTS of comments and the 100th line is the closing parenthesis.

[ivant]

The error indicates the the A register is not connected properly. You probably forgot to connect some of its inputs.

It gives it at the closing parenthesis, as this is the time it read the whole definition.