As far as Lord Caitanya was concerned, He said that He did not understand the explanation of Bhaṭṭācārya not because it was too difficult for His understanding but because He did not approve of the Māyāvādī interpretation.
When the Lord said that He was an uneducated fool and could not follow the expositions, Bhaṭṭācārya replied: "If You do not follow what I am saying, why don't You inquire? Why do You simply sit silently? It appears that You do have something to say about my explanations."
"My dear sir," the Lord replied. "As far as the Vedānta-sūtra or the codes of Vedānta are concerned, I can understand the meaning quite well. However, I cannot understand your explanations. There is nothing really difficult about the meaning of the original Vedānta-sūtra, but the way you explain Vedānta-sūtra appears to obscure the real meaning. You do not elucidate the direct meaning but imagine something and consequently obscure the true meaning. I think that you have a particular doctrine which you are trying to expound through the codes of Vedānta-sūtra."