I don't really believe in writer's block. I think if a writer finds themselves consistently unable to create, it often boils down to fear of failure. The solution to fear is ACTION. So take action - start writing and don't stop. Write about anything at first, it doesn't matter. Just keep the wheels greased and keep going. Before long they'll be back to their old selves and the inspiration will be there again. Keep working, keep pushing, don't give any power to the fear, and writer's block will not be a big problem.