Full Idea
A problem with the theory theory of concepts is that it is holistic, saying a concept is determined by its role, not by its constituents. It then seems difficult for different people to possess the same concepts (or even the same person, over time).
Gist of Idea
The theory theory is holistic, so how can people have identical concepts?
Source
E Margolis/S Laurence (Concepts [2009], 2.3)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.9
A Reaction
This seems a good objection to any holistic account of concepts or meaning - spotted by Plato in motivating his theory of Forms, to give the necessary stability to communication.