What is the ruling on an Imam leading people in prayer when he is unfamiliar with the rules of Tajweed?

The worshiper must recite the Qur'an correctly, especially the Imam, due to his knowledge of Tajweed rules and their application. If an Imam leads the prayer and is not proficient in Tajweed rules, his prayer is valid but disliked, as long as his recitation is correct and does not alter the meaning. However, if the Imam makes a mistake in Al-Fatihah that alters the meaning, such as pronouncing the taa’ in "an'amta" with a dammah or the kaaf in "iyyaka" with a kasrah, his prayer and the prayer of the congregants become invalid.