How to fix `RIGIFY ERROR: Bone 'spine.004': Cannot connect chain - bone position is disjoint. Incorrect armature type for type 'chain

Today I was rigging a character in blender. I modified a Rigify armature, then clicked Rigify and got this error:

RIGIFY ERROR: Bone 'spine.004': Cannot connect chain - bone position is disjoint. Incorrect armature type for type 'chain_rigs'

What does it mean ? Just to confirm, I created a new scene, a brand new Rigify rig and clicked "Rigify" directly. This time it worked. Then I canceled the operation, moved the top bone in the spine, and clicked "Rigify" again. The same error as earlier popped out.

So to fix it, I attempted to move the top of the top spine bone to the bottom of the neck bone. I first moved it with G, Z (translation along the Z axis), and moved it approximately to where I wanted, but Rigify still failed. So I ended up using Snap.

Spine bone and neck bone are now "connected"

This time it did the trick, and Rigify completed the rig.

Rigify created the rig.