Armature not working after linking new mesh data So I created a character and an armature that worked very well. I decided to change the legs and feet of my character using a mesh from another character I created (almost identical mesh, with minor tweaks). 

I swapped the linked mesh data from the original character with the mesh data from the new character (just the legs and feet). I renamed the new mesh data to match that of the original mesh data and did the work to apply the same bone weights to the new mesh that the original had (the original vertex groups still appeared in the DATA tab of the PROPERTIES panel, so this was easy).

However, the armature will not move the new mesh (but it still does move the rest of the body). Any thoughts on how to resolve this?
Logistically speaking, If it is now a single mesh with verts associated with vertex groups with the appropriate bone names from the armature that it is already parented to, it should work. 

I just ran some tests on a rig that I have. I added a cube in Object mode, joined it to the rigged mesh, in Edit mode I copied the vertex groups associated with a vert in the original mesh, went into pose mode and it worked without a hitch.

If you upload the .blend I'll take a peek.