With a Lite Inventu Viewer License, you do not have the Multiple-Protocol feature which is required to support more than one of the protocol families (3270, 5250 or ASCII).
You Need to remove un-used host definitions or upgrade license to mult-protocol.
Check your Host Definitions--if the sample 'Insure' host, which is 3270 is defined, delete it, especially if it is alphabetically lower (first) compared to your host definition.