She's apathetic about this problem; it doesn't matter to her at all.

That explanation helped me understand the problem.

Your presence creates a difficulty for everyone.

The solution to that problem is simple.

We need to solve the hammock problem quickly.

So I want to say to all of you: Courage! This disease will not disrupt our lives forever. The current difficulties will vanish, ordinary life will appear again.

Unfortunately, the lack of good leadership in our clan is a problem.

He treated my idea as one—i.e., an idea—that creates a problem.
(He treated my idea as though it created a problem.)

Unfortunately you don't understand how complex this problem is.

The more people, the more problems.

I have . . . um . . . a slight problem.