Do people still use this expression? I haven't heard this usage in years, so assuming it is not as common as it once was, I added an explanatory note.
NURUPO.
Short for "null pointer", a kind of software error. When a program encounters a null pointer unexpectedly, it typically causes the program to crash. By analogy, a character undergoes "nurupo" when they experience the mental equivalent of a system crash (such as from exposure to excessive amounts of what). The English expression "mind=blown" is roughly equivalent.