Sorry to hear that. Please note the backup folder is created only if:

- You have created a synchronized folder using DriveHQ FileManager;

- You deleted a file (or folder) in a synchronized folder;

- DriveHQ FileManager will automatically delete the corresponding file (or folder) in the other sync-ed folder. Before FileManager automatically deletes the file, it creates a special backup folder: _DHQ_SyncCache_

It is recommended using DriveHQ Online Backup to protect your files / folders. When files are backed up using DriveHQ Online Backup, even if you delete the source files / folders, it won't delete the files / folders on server.