This error occurs when you duplicate an activity or import activities.
I recently implemented master/slave mysql database.
This error occurs because it reads the backup_controller record too quick after insert the record.
The solution is just add
“sleep(1);”
before:
if (! $controllerrec = $DB->get_record(‘backup_controllers’, array(‘backupid’ => $backupid))) {
throw new backup_dbops_exception(‘backup_controller_dbops_nonexisting’);
}
in line 105, moodle/backup/util/dbops/backup_controller_dbops.class.php
and
in line 94, moodle/backup/util/dbops/restore_controller_dbops.class.php
