There are many possibilities as to why the Tupgrade Tool is enable to find the RemotEye card. Here are some steps that can be performed to ensure proper connectivity. 

Steps

1. Please make sure you have the latest version of Tupgrade Tool.
   • You can download the latest version from the website at https://www.toshiba.com/tic/power-electronics/uninterruptible-power-systems/monitoring-solutions/remoteye4 -> View Technical Downloads -> Software Tab -> Toshiba RemotEye Firmware Upgrade Utility (Tupgrade) Version x.xx
2. Open the Tupgrade Tool using Administrator access
   • Administrator privileges enables raw socket functionality and allows to search for RemotEye behind the router. Without admin privilege's Tupgrade will only discover devices on its network segment.

3. If still does not work with administrator then, you may need a local admin account. If you are using a company laptop there is a high possibility that the computer has some permission setup. 

Why do Raw sockets require Administrative Rights?
On Windows, Microsoft restricted Raw sockets access due to security concerns in Windows XP and have required a user to have administrative rights in order to create them ever since:
Raw sockets offer the capability to manipulate the underlying transport, so they can be used for malicious purposes that pose a security threat. Therefore, only members of the Administrators group can create sockets of type SOCK_RAW on Windows 2000 and later. (From Microsoft Docs)

Direct Connection

1. If all else fails then setup a direct connection with static ip on both RemotEye and Computer.

Console log into the RemotEye card using software such at Putty, navigate to the ipv4 section and change the ip, gateway and mask. Configure the computer network port to be on the same network by assign it the same gateway and mask but assign the computer its own unique ip.

Refer to RemotEye 4 User Manual page 69-74.