The issue occurs when the instance Number is changed. After the instance number is changed the MNB-1000 will look normal in the current WorkPlace Commissioning Tool (WPCT) session, but the next time WPCT is opened the MNB-1000 will either be unable to be found or the controller icon will be displayed as a gray rectangle with a question mark in it.
Selecting Extended Data will cause a loss of communications with the controller as signified by red exclamation point (!).
TAC I/A Series
Any MNB-1000 with 1.510 firmware
This is a firmware issue present in 1.510 only.
Cycling power to the MNB-1000 after changing the instance Number will correct the issue.
Once communications is established upgrade the MNB-1000 firmware version 1.511 to prevent the possibility of this happening in the future.