The moment you point the finger at someone criticizing or judging them:
Look how many fingers point at you! Humans have problems with communication. You, me and everyone else. Unfortunately we don't learn that in school. And some people never learn to communicate. It is a life long journey. We have to switch from "me" to "you". A conflict is not about being right. It is trying to really understand the other one. And please try to understand and be understood. We all are not perfect. We see and experience things differently. If we fight, criticize each other and trying to be right and make the other one feel wrong, we will not find a solution. This is one reason why relationships fall apart.
LACK OF GOOD COMMUNICATION. LISTEN, DON'T POINT YOUR FINGER, TRY TO UNDERSTAND AND BE UNDERSTOOD. It's not about who is right or wrong. It's about how can we fix this as a team.
HOW can I be a better communicator? Education! There is a lot of good imformation online.
But for starters, what worked best for me: Let the other one finish their thoughts, without interruption. Let the person speak so long until they have nothing to say. Then take a pause, think about what has been said. Now it's your turn. Ask the other person to return the favor, to talk without being interrupted.
That's the first step. Being a good communicator and problem solver takes a life time of learning.