So has this ever happened before?
Once again you have to realize that we exist in a state of maybe.

And unless it is something as basic as I want to move my arm, I move my arm, I know I did it, I can prove I did it, but I think therefore I am and only I might believe that I did it.
If I did it in a forest, or did it anywhere demons might deceive me according to Descartes.

So that's the caveat.

There exists a lot of intel from elsewhere in this world and secret codes that can be cracked numerology systems in use by matrix personnel and AI operating systems, and the use of mythology for universal communications which are in context because the mythology is shared.
So then you can say well you know Zeus, well like that.
So a context for communications based on stories that describe the personality of the characters so that you can refer to characteristics of people via the archetypes, and then discuss things in a myriad of ways. Using a form of compression since to first explain who Zeus is in mythology what mythology is etc is going to be a lot of text you are trying to transmit in a picture rather than flash a picture of Zeus in your mind.

So like all forms of compression of this type, the decoding already exists at the other end so you don;t send all the data, you refer to existing data clumps.
Like object oriented programming. It is kept simple because you call a function from a DLL and it is way over there you don;t know what is in the black box and don't care that is unnecessary information, you just need x and so you use a function call and get the result without needing to know everything in that black box.

Ok so numerous forms of secret communications exist in this world including secret documents in all governments and wherever and black ink.

Now it is possible if you know the codes to decipher messages like the hieroglyphs. It is somewhat possible they have attached different meanings to the symbols and created a false language interpretation.
Only a great deal of work might find that and frankly unless they find some real alien technology we just assume that anyone who mummified that many ibex probably has nothing important to say.
So we really don't care.

But if we do care because we thirst for knowledge about zombies, then why are there so many zombie stories and why does it exist in our culture?

Well people have been known to lose sentience due to accident or injury.
We also know that if they have neither sentience or instincts they go catatonic.

So we always blame the physical brain.
Since that is the evidence we have.

However if the system went down, lets say the machine responsible for actually running the software in this simulator, as real as everything appears it is still computer code and still software running so then it would occur.

How would we know it did? If our consciousness was run on a different machine that did not go down.
And that has happened.
According to intel that exists in innuendo in code etc in artifacts and in matrix common knowledge.

So 2012 was the maintenance cycle for the machine that provides sentience you can see in the center of the Aztec calendar that he is a dead monkey. In 1992 we replaced the simulator so that he would not go down and even got a new operating system AI out of a box and trained him in case he did go down.