There are problems, there are challenges, and there are obstacles. They’re not the same.
Harrison Ford got sick on the set of Steven Spielberg’s film Raiders of the Lost Ark.
One morning, scheduled for an intense sword fight scene with a formidable foe, Ford didn’t feel up to the task. So, he asked Spielberg to make a change. Spielberg agreed. Out of sheer necessity, Ford made a creative choice, a choice that would make for arguably the film’s most memorable scene.