Client doesn't find QNAP server

Client is unable to find the server.

QNAP TS-459U+
Client version 2.5.7
Server version 1.9.3

Also installed V2 manually from your website. But no luck.

#2

OK, perhaps you network is blocking udp broadcasts. In the client right click USB Hubs -> Specify Hubs then add your server ip of your qnap and the port is 7575