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: www.yoursite.com/whmcs/install/install.php
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 https://download.whmcs.com
2. Agree to the End User License Agreement.
3. Click Continue at the bottom of the next screen:
4. Make a backup of the WHMCS MySQL database.
5. Click Start the Upgrade.
The database update process will now commence:
Within a few minutes, a success message should be displayed:
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:
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