The simulation we live in is abandonware.

@seachaint Maybe. Or maybe they'll just say "oh, shit, there's that weird glitch again. better reboot the system".
There was also an argument I read that went essentially: "eventually in a universe with any sentient beings complex simulations will be developed; the nature of simulations is such that there will be many more simulations than there actual universes, and so the odds are that we're in a simulation" (the argument was a bit more sophisticated than this).