IPv6 needs to be disabled on LES App and Client and LIMS App  servers. To check IPv6 status:

-Open Network and Sharing Center on the server

-Mouse click on Ethernet card used for server network connection, for example "Ethernet0"

-Mouse click on "Properties" tab | locate "Internet Protocol Version 6 (TCP/IPv6)" on the list and make sure the box next to it is unchecked.