Error on NC drill (by layer) output file

Hello,

I am designing a 4 layer board with some blind/buried vias. So on “Manufacture -> NC -> NC Drill” I selected under “Drilling” the option“By layer”. There are then generated 3 output files “file-1-2-np.drl”, “file-2-3-np.drl”and“file-3-4-np.drl”.

In order to probe if everything was all right, I placed on the board 4 mounting holes (the same symbol four times), but on the output files 1-2 and 2-3 I got

X17000Y-17000

X-17000Y-17000

X-17000Y17000

While on the file 3-4 I got

X17000Y-17000

X-17000Y-17000

X-17000Y17000

X17000Y17000

So, one of the hole is only visible on the last layer; something like a blind via but it is actually a passing though hole. I repeated the process several times and the output was always the same. In fact, I discovered that the last hole that I place on the PCB is the one that has the error on the output files. If I choose the option of “Drilling” “Layer pair”, the output file is correct.

Am I missing some configuration? Or maybe am I doing something wrong? Any ideas?

I’m using Allegro PCB designer 16.5

Thank you very much.