That is explained. Śaṅkara is the incarnation of Lord Śiva. He has no fault. He has simply executed the order of the Supreme Lord. But the way in which he has presented the commentary, one should not hear it. That is Caitanya Mahāprabhu's warning.
Pradyumna: "Śaṅkarācārya, who is an incarnation of Lord Śiva, is faultless because he is servant carrying out the orders of the Lord, but those who follow his Māyāvādī philosophy are doomed. They will lose all their advancement in spiritual knowledge."
Prabhupāda: This is the opinion of Caitanya Mahāprabhu. Anyone who hears Śaṅkara's comment on Vedānta philosophy, he is doomed.
Professor: That's about it.
Prabhupāda: What is the purport?
Pradyumna: "Māyāvādī philosophers are very proud of exhibiting their Vedānta knowledge through grammatical jugglery, but Lord Śrī Kṛṣṇa in Bhagavad-gītā certifies that they are māyayāpahṛta-jñānāḥ (BG 7.15), bereft of real knowledge due to māyā. Māyā has two potencies with which to execute her two functions: prakṣepātmikā..."
Prabhupāda: Prakṣepātmikā.
Pradyumna: "...śakti, the power to throw the living entity in the ocean of material existence, and āvaraṇātmikā-śakti, the power to cover the knowledge of the living entity. The function of the āvaraṇātmikā-śakti is explained the Bhagavad-gītā by the word: māyayāpahṛta-jñāna. Why the daivī-māyā, or illusory energy of Kṛṣṇa takes away the knowledge of the Māyāvādī philosophers is also explained in Bhagavad-gītā by the use of the words āsuraṁ bhāvam āśritāḥ, which refer to a person who does not agree to the existence of the Lord. The Māyāvādīs, who are not in agreement with the existence of the Lord, can be classed in two groups, exemplified by the impersonalists Śaṅkarites of Vārāṇasī and the Buddhists of Saranātha. Both of them are Māyāvādīs, and Kṛṣṇa takes away their knowledge due to their atheistic philosophies. Neither of them agree to accept the existence of a personal God. The Buddhist philosophers clearly deny, clearly deny both the soul and God, and although the Śaṅkarites do not openly deny God, they say that the Absolute is nirākāra, or formless. Thus both of them are aviśuddha-buddhayaḥ (SB 10.2.32), or imperfect and unclean in their knowledge and intelligence."
Prabhupāda: What do you think?
Professor: That's... Of course, in the introduction to Śaṅkara's commentary to Bhagavad-gītā, he does, it seems, if it is for him, which is that...
Prabhupāda: He accepts Kṛṣṇa as the Supreme Personality of Godhead.
Professor: Yes, Kṛṣṇa, yes.
Prabhupāda: Yes.
Professor: So Śaṅkara is a bit difficult because his followers, even he's Māyāvādī, the followers, even the followers, they clearly believe in it. But whether, what Śaṅkara himself meant by it...
Prabhupāda: No, that is explained. Śaṅkara is the incarnation of Lord Śiva. He has no fault. He has simply executed the order of the Supreme Lord. But the way in which he has presented the commentary, one should not hear it. That is his warning.