2X application server 5.1 is installed in Windows 2k3 R2 SP2. 2X clients can connect to the server over the LAN, but NOT over the WAN which connected with site to site vpn using ISA 2006 on port 80. Client can ping and RDP to the 2X server over the WAN and can also browse intranet over the WAN using port 80. Client can also browse 2X server on port 81. The error code is: Code [01/00000004] The specified remote 2X application server could not be found. could you please shed some light on how to troubleshoot the issue? Thanks