In a new update rolling out to Pokémon Go, there was a short period of time where players could teach Primeape a move it normally wouldn’t be able to learn in the game.
Primeape, a Fighting-type Pokémon known for its speed and physical attack, was one of several Pokémon to receive the ability to learn a new move through the use of TMs. Niantic previously announced Primeape would gain access to Ice Punch, but players could instead teach it the Water-type variant of Weather Ball.
Weather Ball is a special attack that has different variants depending on the weather in the main series, but in Pokémon Go, it usually relies on the Pokémon using it to decide its type.
In the same update that would have given Primeape access to Ice Punch, Kantonian Vulpix gained access to the Fire-type Weather Ball, while Alolan Vulpix got the Ice-type variant. It is very likely some small internal factor led to the error which allowed Primeape to learn Weather Ball, too.
Niantic has already addressed part of the problem, but is still looking into the main cause of the error, and Primeape will be unusable in the Battle League, which launched with Season Six Part Two today, until further notice.
“A small number of Trainers were able to use TMs to give Primeape attacks it should not be able to learn due to a brief error on January 11 (PST,)” Niantic said. “While the root cause of this error has been resolved, Primeape has been disallowed from Great League as we continue to investigate.”
Primeape has also been placed on the Pokémon HOME banlist for transfers. This is likely a precaution to keep any other errors from being exploited while the developers look for a fix.
Players can likely expect a forced fix to be applied across Pokémon Go that will replace Weather Ball with Ice Punch on any Primeape that was taught the illegal move sometime in the future.