A malformed configuration payload from Google’s Firebase Analytics service crashed iPhone apps at launch on Monday evening. Google rolled out a server-side fix about two hours later. Developers did not have to ship an app update, and users did not have to reinstall anything.
What broke
Firebase is Google’s app-development platform, and its Analytics SDK is bundled into a very large number of iOS apps. Part of that SDK fetches experiment configuration from a Google endpoint. On Monday, the response coming back from that endpoint was incorrectly formatted.
The SDK parsed it into a nil dictionary key, which killed the app at launch. Any iOS app with Firebase Analytics integrated was exposed to it. Google says it is still looking into the underlying cause and has promised a follow-up. As of September 29, the GitHub issue tracking the incident is still open.
Worth noting for anyone whose phone did the crashing: a vendor’s server-side push changed how installed apps behaved, with no warning and no opt-out at the user’s end.
Timeline of the outage
- September 28, 17:41 US/PDT — Crashes begin.
- September 28, 19:52 US/PDT — Google finishes rolling out its fix, about two hours and 11 minutes after the issue started.
- Up to four hours after that — Apps holding a cached copy of the bad payload could keep crashing.
- September 28, 23:52 US/PDT — The point Google’s later summary gives for full resolution.
That last figure comes from Google’s own after-the-fact write-up in the Firebase iOS SDK issue thread, posted by Google software engineer Nick Cooke:
The issue was fully resolved on 2026-09-28 at 23:52 US/PDT.
Google also apologised for the disruption in the same update.
What developers saw
The GitHub issue on Google’s own firebase-ios-sdk repository drew more than 500 comments by September 29. Reports landed from many unrelated apps at the same time, which is how the scale became obvious. As of September 29, Google has not shared a total for affected apps or users.
One developer logged 56 crashes across 56 users in the first 18 minutes. Another, working on the CamperMate app, counted 87 crashes across 87 users on three released builds. Both numbers are individual developers’ own counts, not Google figures.
Source: Firebase iOS SDK on GitHub, 9to5Google
