Cesium collapses when i press "simulate" button in Unreal

Cesium collapses when i press “simulate” button in Unreal
What cause this and how to avoid? (the world terrain disappear)

In Simulate mode, only cameras in the level are used to select tiles. The Editor camera that is shown in the viewport is intentionally not used to select which parts of the model to show (and their level-of-detail). So if you don’t have any cameras in the level, or if they’re far away from where the viewport is looking, you’ll see nothing.