CC Link LT

While commissioning CC Link LT network, Initially i connected 42 stations, all this stations was in network and working properly,
But when i add 2 more stations, Then some random stations was down,
(Not showing in diagnosis also)!!
Can anyone answer to this..

Check your voltage levels you may have to change the size of your terminating resistors to rebalance the signals. Here is a copy of the CC-link installation guidelines