Liveupdate administrator 2.3 download updates from n external liveupdate server

Hi,

I have a Liveupdate administrator 2.3 configured to udpate from an external LUA server but its unable to download update from it.

I tested the connection by clicking on TEST ans it said connection is successful, there is more than enough hard disk space( 50 GB).

What log should i refer and what can be done to fix this issue.

Thanks in advance.