The replace function requires communication with the Control program, which normally is established in the background.
Check that the replacing tablet has connected to the SAME WiFi network as the BridgeTab that you are to replace uses; and that the signal is good.
BT ADMIN n/a
i. BT Admin is running
ii. The BridgeTab has connected to the IP that BT Admin shows, c.f. BT Adminís IP.
There is a lot of data to exchange so it can be that the control software is busy.
See the communication memo.