We investigated reports of iOS app crashes affecting version 12.1.0.

The issue was caused by a Firebase Analytics for iOS incident where an incorrectly formatted experiment payload was served by Firebase’s backend. This caused affected apps to crash during Firebase Analytics experiment processing on launch.

Firebase reports the incident began on September 28, 2026 at 8:41 PM EDT and their backend fix was fully rolled out by September 28, 2026 at 10:52 PM EDT. Due to SDK caching behavior, some users may have continued seeing crashes until approximately September 29, 2026 at 2:52 AM EDT.

No app update is required for this fix. The issue was resolved by Firebase on their backend.

Reference: https://github.com/firebase/firebase-ios-sdk/issues/16728