Full Idea
Since Russell did not want to introduce non-existent objects, or declare many sentences meaningless, he prevented the problem from getting started, by denying that 'the present King of France is bald' is really a subject-predicate sentence.
Gist of Idea
Denying definite description sentences are subject-predicate in form blocks two big problems
Source
report of Bertrand Russell (On Denoting [1905]) by Graeme Forbes - The Metaphysics of Modality 4.1
Book Reference
Forbes,Graeme: 'The Metaphysics of Modality' [OUP 1985], p.74