the variabila ParentPlant (is
reference to bp i have setup this)
Can we see how you set it up? Creating an actor variable does not accomplish much. It’s empty, pointing at nothing - hence the error.
Think of it as of a text string, you created a variable but you forgot to type in the actual text.
So, show us how you Set the reference of the Parent Planet actor. If you have 15 planets, how does the editor know which one you mean?