Apply and recover an exact-baseline core update

Where: Admin → System → Maintenance → Package Manager

Before you start

Upload does not apply. A mismatched baseline withholds Apply. Release library metadata edits/removal do not modify installed forum files. A package already applied is retained for download, not reapplied.

Step by step

Record installed edition/version and take a full verified backup.
Upload the exact-baseline incremental ZIP under Install an update; use Upload & review.
Review target/source, checksums, database changes, file plan and blockers. A fresh installer is stored for download, never applied over the existing board.
Use Apply update only for an accepted matching package. Wait for completion; do not start a second apply.
Review installed/database versions and History. If files verify but the database half is incomplete, use Finish database upgrade / Retry database upgrade.
For rollback select the archive’s recorded restored version/time, understand newer data loss, then verify restored files and database.

Settings and behaviour

The updater takes a pre-update backup and serialises application with a lock. An interrupted request may leave a retryable database half; use the explicit recovery screen instead of manually inventing a version stamp. A stale lock clears after its configured window (ten minutes in this release); inspect History before retrying.

Check the result

Verify the version from disk, database upgrade record, History and guest/member smoke tests: sign-in, topic/reply, upload/download, theme and addon settings.

Common questions and troubleshooting

Blocked update: get the exact edition/from version. File newer than DB: follow the manager’s proven-package retry or System & upgrades instruction. Rollback refused: archive must be readable/verifiable.