Black box design modification

Logisim Projects
1

after sending my .circ file to validation i have recived the following feedback:
Violations found:

  1. blackbox design modified in 3_bit_carry
  2. blackbox design modified in tautology
    i have compered my project with the original .circ file you’ve uploaded and it didnt seem to have a diffrence.
    would you please help me understand whats wrong with my file?
    what does “blackbox design modified” mean?
2

In both cases, you have added extra outputs, and connected them to your circuit, instead of using the ones provided in the template.

Adding extra outputs is equivalent to adding extra output pins in the blackbox design. Hence, your blackbox design is not the same as that in the template.