Ok, sorry, that was not your fault. I was over-simplifying.
Here I made a project that works for sure.
So the problem is that it’s tricky to cast to placed actors out in the world. Best way to cast to them is to spawn them in the game mode and then assign a variable to them. So then you can call the variable.
First, I made an explosive barrel BP Class, but didn’t put it in the world. Inside I made the function to destroy it.
Here:
Next, I Spawn the barrel in the world and create the widget. All done in the game mode BP. Once I spawn the barrel actor, I assign it to a variable, in this example I made up the name of the variable to be VarExplosiveBarrel01.
Like this:
Last, I go into the widget, select the button, add the OnClick event. Then in the Graph portion I cast to the game mode and then find that variable and then fire the function.
This is tested and works! Tell me if this helps.