Animation [...or UI?] NullReferenceException with no stack trace, with Stack Trace Logging>Full

I'm seeing this error in the 5.3.0f2 editor and Windows standalone builds, and clicking instances of this error in the Console window highlights UI objects in the Hierarchy that contain all of these: Animator, Text (deactivated), Outline and Canvas Renderer components (and RectTransforms, and one custom script that checks for null references before dereferencing). Even with Stack Trace Logging>Full there is no additional info in the bottom of the console when I click the error. Warnings above it are from other objects, so I don't have much to go on.

 

Is anyone getting stack traces from errors or exceptions originating in Unity code (not your own scripts) with Stack Trace Logging>Script Only?

 

The exception appears to be coming after calls to Animator.Play on a controller that has a valid Motion to play on a UI object with a Text component

 

the exception may be fixed in coming builds, but I'd still like to know why there was no stack trace