If you find your SketchUp model starts to disappear, or clip, when you move closer to it but not close enough to pass through an object, you may have an issue with model data at a far off point in the scene. Usually, you will not be aware of this geometry, it will be out of your normal field of work and typically occurs when third-party data is imported into your SketchUp model. This is a known issue and is normally resolved by cleaning up this distant geometry. Please take a look at the video and links belo to resolve the issue.