Hedera will be upgrading Mainnet to v0.11.0 (release notes:
https://hedera.io/release-notes) on Thursday, Feb 4th 2021 at 18:00 UTC. After this upgrade, the file formats for record streams, record stream signatures, event streams, and event stream signatures will be updated from their current version to version 5; please reference
https://docs.hedera.com/guides/docs/record-and-event-stream-file-formats for notable changes. Changes are currently available on testnet. In addition, mirrornode software users will require an update to v0.26.0 to accommodate for these format changes, available at
https://github.com/hashgraph/hedera-mirror-node/releases.