Backup page leads to blank page

[Willv]

Hi,

I got this case on my older servers (several of them).

When some clients click on the backup button on some domains they get a blank page. Activating php error log get me this error :

Warning: MigrationCManager::require_once(backup/MigrationUploadScout.php) [function.MigrationCManager-require-once]: failed to open stream: No such file or directory in /usr/local/psa/admin/plib/PMM/MigrationCManager.php on line 103

Fatal error: MigrationCManager::require_once() [function.require]: Failed opening required 'backup/MigrationUploadScout.php' (include_path='/usr/local/psa/admin/plib:/usr/local/psa/admin/javascripts:/usr/local/psa/admin/plib/locales:/usr/local/psa/admin/auto_prepend:/usr/local/psa/admin/htdocs/domains/databases/phpMyAdmin:/usr/local/psa/admin/htdocs/domains/databases/phpPgAdmin') in /usr/local/psa/admin/plib/PMM/MigrationCManager.php on line 103

Other domains work fine. Anyway to debug that ?

I got the case on several servers running serveral 8.2ish, 8.4ish version.

Regards.