failed to restore. Error reading source file. The encryption key is invalid

Hi, we reinstalled the server then install DLO and connected to Synology Disk station successfully

copy some old users files to new users folder and try to restore, the below message showing.

any idea how to fix this issue

failed to restore. Error reading source file.
The encryption key is invalid.
The Desktop Agent will remain disabled until the problem has been corrected by your administrator.
Your administrator has been notified.