Vote regression here: https://issuetracker.unity3d.com/issues/in-order-to-call-gettransforminfoexpectuptodate-dot-dot-dot-error-message-appears-while-toggling-skinned-mesh-renderer-component

>> This issue is still occurring with the public build (5.6.0f3).
+1
But it says "Voting disabled for resolved issues (Fixed)"

This issue is still occurring with the public build (5.6.0f3). Is this fixed in one of the betas?

Still active unity 5.6.0f2 i just got the error.

Still here in 5.6.0f3

Maybe time for fixed?

Still here in 5.6.0f3. Shows up whenever rigidbodys are set to interpolate.

Is anyone at Unity still working on this? It's marked as resolved, and voting is disabled, but clearly a number of people still have this problem in the release version (5.6.0f3). I'm not seeing any new bug reports though, even though I filed one myself a few days ago. This is still the only hit I get when I search for this problem.

My solution sadly did not hold, BUT I found a SOLID way to reproduce this bug.
It isn't rigidbodies, perhaps that was it during the beta version but you can reproduce easily now even on a brand new project with NOTHING inside on the "stable" release of 5.6.0f3 following these steps.
Took me a painstaking amount of time toggling components to narrow this down.
I filed a bug report so will be helpful if you guys voted on it. Will post back once the report is verified
Try the steps I mention and you'll see :)

1. Create a brand new project, lets start fresh.(no need to import anything)
2. In the scene, create a Spotlight > Change "Shadow Type" to "Soft Shadows"
3. Keeping that Spotlight selected > Create > 3D Object > Cube (to make it a child of the light)
4. Change Cube's position to (0, 0, 1)[x, y, z] {so it is directly below Spot Light}
5. Add "Skinned Mesh Renderer" component to this Cube. (leave Mesh Renderer as is)
6. Keeping this Cube selected > Create Empty Child (creates empty GameObject as child of Cube)
7. Select Cube, drag the empty GameObject to the "Root Bone" of the "Skinned Mesh Renderer" component.
8. In the Scene View, making sure the cube is visible, toggle "Skinned Mesh Renderer" rapidly and if everything was done right, you should see the following error message
"In order to call GetTransformInfoExpectUpToDate, RendererUpdateManager.UpdateAll must be called first."

The important elements of this bug reproduction are Spotlight, Realtime/Mixed Shadows(hard/soft), "Skinned Mesh Renderer" with "Root Bone" assigned.

Still happening in Unity 5.6f3 , wasn't happening in Unity 5.5

I've got this issue, too, on Unity 5.6.0f1 Linux.

For me, a mirror plane (of the non-rendertarget veriety) seems to the be issue. The mirror stopped working and whenever it enters the camera, I get the warning once (and then only again when it was off-camera for a moment).