accessing umg blueprint from character blueprint.

hey everyone, so i created and inventory in a widget blueprint. all i want to do is that, on the press of the I key, it switches from visible to hidden. now i can’t do that on the widget blueprint itself, so i want to do it inside the character blueprint from the third person template. I followed the instructions on the Blueprint Comms document page:
https://docs.unrealengine.com/latest/INT/Engine/Blueprints/UserGuide/BlueprintComms/index.html

but i get stuck on the part where they set the default.

so here’s what i did. my widget blueprint is called MainHUD. i created a variable in the character blueprint which is the object reference of MainHUD. i created a tooltip and made it public. now when i go to the defaults tab and try to set a value for that variable, nothing shows in the little box that pops up.

i have searched everywhere for help and decided to ask here. so if anyone has a solution, that’d be great. i figure i’ve given enough information, but if you need more, don’t be shy to ask.

and sorry for sounding so n00by, but i just started with unreal engine, so yeah.

anyway, thanks to anyone who helps.

PitStopGames.