Hello. I also have the same problem. The first few days we all had access to the UM3 in our office. Now, without changing anything in the it-infrastruture, some computer have no connection to the UM3. Also a ping to the IP adress isn't possible. It seems like the UM blocks the connection. With another PC in the same IP-Range an the same firewall-options access is possible, next day another PC could connect and an other not... very curious. The firewall notes no blocked packages... Could anybody help me?