have you checked that the command you used to click on the character can interact with characters or both character & objects - you can find the options under the "command properties" tab for the interface.
you created a new npc object? you mean an object for assigning the position of the npc character on the scene yes? you assign npc characters to scenes in the same way that you would do for your playable character.
also I assume that you have created a dialog box & assigned all the relevant font files for them?
if you can't figure it out, then - if you wouldn't mind - could you please post some screenshots of your setup such as interface, actions & so on please, as I find it much easier to work out problems visually; plus I can usually spot what you may or may not have done pretty quickly.
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