[Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v0.12.9-rc.1...v0.12.9-rc.2) * Implement aggregation by error type for tracked decryption failures [\#2045](https://github.com/matrix-org/matrix-react-sdk/pull/2045) * make new hiding of roomsublist behaviour opt-in [\#2044](https://github.com/matrix-org/matrix-react-sdk/pull/2044) * Implement aggregation by error type for tracked decryption failures [\#2043](https://github.com/matrix-org/matrix-react-sdk/pull/2043) * make new hiding of roomsublist behaviour opt-in [\#2030](https://github.com/matrix-org/matrix-react-sdk/pull/2030)