This is an important skill when it comes to designing in general. Without the ability to solve problems well, I personally don’t think you can become a successful designer. Solving problems within a design is important, but also is there’s issues in the communicating side of the design. You have to be able to solve problems if you run into them and reach out to the client to do so. If you have a question while designing for someone else, it’s better to simply ask instead of try to guess.