An update that did not complete.
WHAT USUALLY HAPPENS
The update downloads, begins, and fails partway, leaving files in a mixed state.
IMMEDIATE ACTION
If you took a backup, restore it. That is why you took it.
COMMON CAUSES
Insufficient disk space Permissions preventing writing A timeout on a large update Memory exhaustion An incompatible PHP version A conflict with another extension
RECOVERING MANUALLY
Download the current version from the official source, and upload the core files over the existing ones, preserving your configuration, uploads and custom content.
Most applications support this. Check the documentation for what to preserve.
MAINTENANCE MODE STUCK
Some applications leave a maintenance flag file when an update fails. Delete it to restore the site.
AFTERWARDS
Run any database update routine the application provides. A code update without the database update leaves them out of step.
PREVENTING RECURRENCE
Back up first, check disk space, raise time limits, and test major updates on a staging copy.
