Error restoreCD : No backup clients found on the backup server

Restore
1

i upgrade urBackup server from 2.1.20 to 2.2.7 and after restoreCD give me this error : No backup clients found on the backup server

try to upgrade to 2.2.8 and same error

server:
windows 2011 homeserver (urbackup v2.2.8)

clients :
2 windows 10 pro x64 (urbackup client v2.2.5)
1 rpi debian jessie (urbackup client v2.1.16)

clients are in a group
there is no client in default group

2

You got a single server on your network ?
There were a few issues on the forums with forgotten test server with empty password, that the cd was connecting to.

3

OMG ! just testing OpenMediaVault at the same time and forgot to shutdown urBackup on it !
Thanks