What is the ruling on praying behind an Imam who makes a meaning-altering mistake in reciting Al-Fatiha, and there are reprehensible innovations in the mosque after the prayer?

If someone makes an error in reciting Al-Fatihah that changes its meaning, their prayer is invalid, whether they are an Imam or a follower. They must learn Al-Fatihah and correct their recitation. It is not permissible for someone who recites it correctly to pray behind them. However, if the error does not change the meaning, their prayer is valid, but it is better to pray behind someone who does not make mistakes. Also, repeating "Ya Latif" a hundred times is an innovation (bid'ah).