It appears there is a bug in the railing object: if it is placed associated with a stair, and the stair flight ends with a riser, then the segment interior post setting to place a post at every riser will not function. Whether the stair starts with a riser or tread appears to have no impact.
In the first image, everything works with a stair ending in a tread:
When the stair is changed to end in a riser, railing inner posts stop working as expected:
Still looking?
