iPhone Field Test not working on my iPhone

Help 3001#12345#

When I dial this from my phone instead of getting a detailed response like everybody else gets, I get an unknown error message that says “an error occurred unknown error”.

I have strong reason to believe that my ex is able to target my location in real time, as he always seems to know where I am and I’ve checked my vehicle for a tracking device and found nothing. i’m unable to get any sort of results from dialing that code. I should see a page of results according to all of these forums. I just get an unknown error occurred anyone know what this is about or why?

[Re-Titled by Moderator]