Guides & TutorialsTroubleshootingTroubleshooting UpdatesTroubleshooting a Down for Maintenance Error while Updating WHMCS

Troubleshooting a Down for Maintenance Error while Updating WHMCS


While updating, you may see a Down for Maintenance (Err 2) error when you visit WHMCS.

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

WHMCS\Exception\Application\InstallationVersionMisMatch: Database version '7.6.2-release.1' does not match file version '7.7.1-release.1'
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The specific version numbers will vary, but the reported database version will be lower than the file version.


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


To resolve this issue:

1. In your browser, go to the /install/install.php file in your WHMCS installation's directory. For example,

If a 404 Page Not Found error displays, upload the /install directory and its contents to your server. You can download this as part of the Full Release Version files at

EULA Screen

2. Agree to the End User License Agreement.

3. Click Continue.

Click Continue button

4. Back up the WHMCS MySQL database.

5. Click I have a backup, start the upgrade.

Click I have a backup, start upgrade button

An Upgrade In Progress message will display while the upgrade process runs.

Upgrade in Progress

Within a few minutes, a success message will display:

Upgrade Completed Successfully!

If an Upgrade Failed message displays, see Updating WHMCS.

6. Delete the install subdirectory from your server.

7. Click the link to return to the Admin Area.

8. Ensure that the version number in the Admin Dashboard sidebar or in Configuration > System Health (Help > System Health Status prior to WHMCS 8.0) is the version you were updating to.

After you complete the update process, if you have not done so already, we recommend reviewing the Release Notes for your new version.