Why can't 3 surfaces sharing a common edge be knitted together ?

Hi,

What is the logical reason behind this? (or is it possible and I don't know?)

In below illustration I can knit any 2 surfaces together. But when i try to knit all 3 surfaces together or 2 surfaces at once and then knitted surface with the third surface it throws error. All the three surfaces share a common edge.

Practical application is when I try to knit the 'tent-like' surface on top of base surface the error appears (there surfaces - split face, base surface and tent-like surface have a  common edge). But I can knit if i delete the split surface before making the tent-like surface.

SolidworksSurfacing