Full Idea
Having rejected the syntactic approach and the meaninglessness view, one might feel that the last resort for explaining the defectiveness of category mistakes is to claim that they are truth-valueless (even if meaningful).
Gist of Idea
If category mistakes aren't syntax failure or meaningless, maybe they just lack a truth-value?
Source
Ofra Magidor (Category Mistakes [2013], 4.3.1)
Book Reference
Magidor,Ofra: 'Category Mistakes' [OUP 2013], p.91
A Reaction
She rejects this one as well, and votes for a pragmatic explanation, in terms of presupposition failure. The view I incline towards is just that they are false, despite being well-formed, meaningful and truth-valued.