Internal problem bias (cf. External problem bias)
The tendency to see our problems as outside of ourselves and as something to fix in the outside world, at the expense of not noticing how much of the problem is an inside problem (an issue within ourselves). It includes the tendency to not address that inside problem first before trying to address any outside problem that may still exist once that is done.
Example: "I'm so fed up with my sister taking advantage of me. I'm going to give her a piece of my mind."
Have you given yourself the right to say "no" to your sister and maintain the boundaries needed to take care of yourself? Have your dissolved any guilt you might feel in doing that by using undoing guilt? Have you asked yourself which of your behaviors may have allowed or stimulated your sister to "take advantage of you"? Have you used undoing fear to let go of any feelings of defensiveness with your sister? All these are possible inside problems to be addressed before deciding what different outcomes you'd like to have with your relationship with your sister.