Guides & TutorialsUpdating WHMCS TroubleshootingTroubleshooting a InstallationVersionMisMatch: Database version does not match file version Error

Troubleshooting a InstallationVersionMisMatch: Database version does not match file version Error

Whilst performing an update, a Down for Maintenance (Err 2) error may occur when visiting WHMCS pages containing a message that the database version does not match the file version.

The full message is shown below:

WHMCS\Exception\Application\InstallationVersionMisMatch: Database version '7.6.2-release.1' does not match file version '7.7.1-release.1'

The specific version numbers will vary, but the reported database version is always lower than the file version.


The WHMCS files from a new version have been uploaded, the updates to the MySQL database have not been completed.


1. Visit the /install/install.php file within your WHMCS directory. For example:

A screen like this will display:

If a 404 Page Not Found error is displayed instead, upload the /install directory and its contents to your webserver. It can be obtained from the Full Release Version files at

EULA Screen

2. Agree to the End User License Agreement.

3. Click Continue at the bottom of the next screen:

Click Continue button

4. Make a backup of the WHMCS MySQL database.

5. Click Start the Upgrade.

Click I have a backup, start upgrade button

The database update process will now commence:

Upgrade in Progress

Within a few minutes, a success message should be displayed:

Upgrade Completed Successfully!

If an Upgrade Failed message is displayed instead, refer to the Updating WHMCS Troubleshooting section for assistance

6. Delete the install sub-directory 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:

You are up to date!

The update process is now complete and you can continue using WHMCS, enjoying the new features and stability improvements of the latest update!

We recommend reviewing the Release Notes