As far as I am aware, omnibenevolence does not mean cannot do evil, simply that the entity does not do evil. Therefore, it is possible to be both.

But yes, if your definitions are correct, then they are definitely contradictory.

I thought omnibonevolant meant all loving and omnipoitent means all powerful?

Then they cannot contradict.

They are not contradicting to one another.

They together contradict a god character however, if that is the underlying question.

no because he has the will to do evil but he does not want to. the fact that he does not want to makes him omnibenevolent.

Based on the Popular definitions of the two words, omnipotence is "all powerful" and omnibenevolent is "all good". If those definitions stand, and for the purpose of this debate, I will suggest they do, then the only issue is that of "evil". If the definition of evil is "The violation of or intent to violate some moral code" I would like to say No, they can coexist. The reason is that moral codes are made up by imperfect beings because of their imperfection. An omnipotent being would not need a moral code because they are perfect. If no moral code is needed, then even if the being is "evil" in our terms, the being would just see it as an act (just like any of the good things the being would do), and not look at the acts as good or evil. Therefore, I believe it to be true that an omnipotent being can be omnibenevolent.