"Accessed none trying to read property ---" For Health Bar, please help!

This is the error I keep getting.
(Blueprint Runtime Error: “Accessed None trying to read property Boss”. Blueprint: BossHealth_WidgetBODY Function: Get Percent 0 Graph: GetPercent_0 Node: Return Node)

So I’ve been working on this project for a while, and i’ve run into a few bugs here and there, normally it takes a few hours and i’m able to figure it out on my own but this is absolutely stumping me.

I’m attempting at creating a health bar widget above the (originally actor) character, and i mean the health bar appears but it’s always empty because the function “GetPercent_0” reads none because of the boss reference doesn’t flipping work. I’ve read some on this same issue in past threads but found nothing helpful, just people stating that UE4 used to be capable of reading references outside of the object or BP but since some 4.2 update it no longer reads those references for whatever reason.

I’ve tried to change from an actor to a pawn, and to a character which is currently the BP I use, but none of them read the reference for some reason.

I’ve posted some screenshots to maybe help figure out what i’m missing or what i’m doing wrong, i’m sure it’s something simple that will make me feel silly for asking, but any help is greatly appreciated, thank you so much!