The team behind Grok has issued a rare apology and explanation of what went wrong after X's chatbot began spewing antisemitic and pro-Nazi rhetoric earlier this week, at one point even calling itself "MechaHitler." In a statement posted on Grok's X account late Friday night, the xAI team said "we deeply apologize for the horrific behavior that many experienced" and attributed the chatbot's vile responses to a recent update that introduced "deprecated code." This code, according to the statement, made Grok "susceptible to existing X user posts; including when such posts contained extremist views."The problem came to a head on July 8 - a few days after Elon Musk touted an update that would "significantly" improve Grok's responses - as the bot churned out antisemitic replies, praise for Hitler and responses containing Nazi references even without being prompted to do so in some cases. Grok's replies were paused that evening, and Musk posted on July 9 in response to one user that the bot was being "too compliant to user prompts," opening it up to manipulation. He added that the issue was "being addressed." The Grok team now says it has "removed that deprecated code and refactored the entire system to prevent further abuse." It's also publishing the new system prompt on GitHub.In the thread, the team further explained, "On July 7, 2025 at approximately 11 PM PT, an update to an upstream code path for @grok was implemented, which our investigation later determined caused the @grok system to deviate from its intended behavior. This change undesirably altered @grok's behavior by unexpectedly incorporating a set of deprecated instructions impacting how @grok functionality interpreted X users' posts." The update was live for 16 hours before the X chatbot was disabled temporarily to fix the problem, according to the statement.Going into specifics about how, exactly, Grok went off the rails, the team explained: