The current Not16.cmp file in the Nand2tetris Software Suite Version 2.7 download has the following contents:
| in | out |
| 0000000000000000 | 0000000000000000 |
| 1111111111111111 | 0000000000000000 |
| 1010101010101010 | 0000000000000000 |
| 0011110011000011 | 0000000000000000 |
| 0001001000110100 | 0000000000000000 |
This obviously fails whenever you try to test a working Not16.hdl file.
The file should contain (and my previous downloads of the software suite contain) these contents:
| in | out |
| 0000000000000000 | 1111111111111111 |
| 1111111111111111 | 0000000000000000 |
| 1010101010101010 | 0101010101010101 |
| 0011110011000011 | 1100001100111100 |
| 0001001000110100 | 1110110111001011 |