Impossible to cast/pass variables? Out of Bounds error on GetAllActors

I cannot for the life of me succeed in modifying a variable between different blueprints. I’ve looked up dozens of solutions, tried multiple methods, with these in particular:

…and also studied Tom’s very detailed youtube video which is linked to via that example, but what seems to be happening is that the casting is failing, and in the log, there is an error that says: “Attempted to get an item from array CallFunc_GetAllActorsOfClass_OutActors out of bounds [0/0]!”

My graphs are posted below - it is more or less the same as demonstrated in the above examples, and I remembered to make sure my variables are assigned to the correct variable type, the eyeballs are all set to public, etc. The BP’s used are the MyCharacter from the ThirdPerson Example (built manually through the instruction video) and the other is derived from HUD, based on what was demonstrated in Tom’s video. This is a pretty basic goal to just add to a score between different blueprints, but I’ve been at this for days and about to give up (or die from an energy drink overdose)… I’m not even sure if it is something I am doing wrong or some kind of glitch. Either way I’m really starting to miss UE3 Kismet where things actually made sense. Any assistance to help me understand what is going on here would be greatly appreciated. Thank you.

What I wrote here before was wrong, what you are doing to get the HUD actually works for me. Have you set your HUD class in the Project settings? It might spawn the wrong HUD class so no actors of your type are found.
Everything else I said is still valid:
To access your HUD you can use the GetHUD function on the PlayerController (use GetPlayerController to get that).
In general you should check your variables before calling functions on it. Like check the count of the array returned from GetAllActorsOfClass or call IsValid on TheHUDVar before calling ScoreUp on it.

Thanks, as you mentioned, it turned out that it was set to the Default HUD and not my custom HUD in the Project Settings. (Maybe there needs to be a warning for calling functions from improperly assigned/unassigned classes?). It seems to be working correctly now!