Adding a CanvasRenderTarget2D* UPROPERTY to a class and setting it using CreateCanvasRenderTarget2D will cause the Editor to crash on load.
This was also reported by a licensee on UDN (https://udn.unrealengine.com/questions/229643/crash-in-46-when-creating-or-updating-a-canvasrend.html) who was able to trigger the crash by calling a function that created a CanvasRenderTarget2D. Retested in main (CL 2375748) and the crash still occurs.
The Licensee that reported the issue narrowed down the issue to using whatever is returned by GetWorld->FeatureLevel. Using ERHIFeatureLevel::SM5 instead works for the Licensee.
Head over to the existing Questions & Answers thread and let us know what's up.