Problem #

You see a Down for Maintenance (Err 2) error while attempting to use WHMCS.

For example:

Down for Maintenance (Err 2) An upgrade is currently in progress... Please come back soon...

Cause #

This message displays when WHMCS cannot run until you finish an upgrade. WHMCS displays it in the Client Area, API responses, cron messages, and to other admins. A routine automatic update displays your Maintenance Message or a Down for Maintenance (Err 3) notice instead, which clears when the update finishes or fails, or one hour after the update begins.

If no update should be running when this message displays, one of these causes applies:

• Your upload included an install directory whose installer you have not yet run. The system displays this message until you finish the upgrade with install/install.php.
• Your PHP files and your MySQL® database are on different versions. A mismatch may occur if:
  • Something terminated the automatic update process before it was complete.
  • You uploaded a new version of PHP files but have not yet performed the PHP update.
  • You applied a patch set to an incompatible version of the software.
  • An automatic update stopped while it was replacing the WHMCS files. Admins see an Update Incomplete page in this case.

In many of these cases, a message may state that the database version does not match the file version. For example:

WHMCS\Exception\Application\InstallationVersionMisMatch: Database version '9.0.1-release.1' does not match file version '9.1.1-release.1'

The system has successfully downloaded the WHMCS files or you have uploaded them, but the updates to the MySQL database have not finished.

Solution #

To ensure that the update process is complete, use the browser method to apply the update.

Last modified: 2026 October 20