ChatGPT Mac app update thumbnail showing bold amber and white text reading “CHATGPT MAC APP / UPDATE OR IT BREAKS” beside a MacBook Pro displaying the OpenAI logo, a red warning alert, and a lock icon on a dark purple-blue neon background.

ChatGPT Mac App Stops Working May 8: How to Update (and What Happens If You Don’t)

On May 8, 2026, OpenAI fully revokes the macOS code-signing certificate it used to sign ChatGPT, Codex, Codex CLI, and Atlas before April 2026. From that day on, macOS Gatekeeper refuses to launch any version still signed with the old certificate, so a perfectly familiar app icon suddenly throws a security warning instead of opening. […]