- None of the UI elements are showing in the scene view.
- The UI layer is hidden.
- If the UI Layer is hidden, un-hide it. To do so just click on the Layers dropdown to the upper right of Unity's Editor and click on the layer you wish to un-hide.
- In now deprecated versions, there was a bug that could cause invisible UI elements. In this case, the solution is to upgrade to unity 5.3 or higher