DLO : Could not connect to server host

Hi

I have a strange problem. Dlo 7.5 is properly installed on Windows 2012.
Firewall is turned off (for testing). Agents are installed correctly. I can telnet from the clients to port 8080 and 8443 on the server. Backup on the client is made to a local resource. However, client can not upload files to the server (although created the directory structure on the server).
The client logs are:

"Failed to copy to the network user data folder. Deduplication failed: Could not connect to server host."

:(

Pleas help!