Unity 5 - Sliding Rigidbodies with maximum friction

I am also experiencing this.

In unity 4.x, stacks of crates would remain still when left undisturbed. Now in 5, occasionally the stacks will begin to slide for unknown reasons.

The stacks are flat, the objects are placed directly on top of each other (they are aligned and not offset). The stacks are resting on a dynamically generated box collider (which has been tested with and without a rigidbody). The sliding does not necessarily occur to the same stacks on each playthrough.

I have tried combinations of increased static and dynamic friction, drag (in case it thought it was falling?), mass increase, project gravity setting increases, and increasing the sleep threshold. Also, assigning or not assigning a physics material, and changing the friction combine type. None of these changes prevent the sliding from occurring.

Any ideas?

Same issue

+1, same issue

Make a bug report.

Same issue here... Is there a bugfix in development ?