Here's a visual:
S2500 stack (MDF) -------- S2500 stack (IDF) ------- S1500 standalone
VLAN 223 has its routed interface on the MDF switch; however, the vlan is configured (i.e., it exists and has a switching profile configured) on the other switches. It is assigned to ports on the MDF switch, not to ports on the other switches.
There are several other VLANs configured on the switches, but this issue of a topology change which I'm unable to identify/verify only references this particular VLAN.
We are using Rapid PVST, not MSTP.