Abu Ahmad al-Hakim: He is not strong according to them
Abu Ahmad ibn Adi al-Jurjani: Hafs ibn Umar has some hadiths, but not many, and his hadiths are individual narrations from those he narrates from, and he does not have any hadith with a rejected text, so I will mention him
Abu Ja'far al-'Uqayli: He narrates from Shu'ba, Malik ibn Mughawil, Ma'sar, and the Imams with fabrications
Abu Hatim al-Razi: Weak in Hadith, and once: He used to lie
Abu Zur'a al-Razi: He is not strong
Ibn Hajar al-'Asqalani: Weak
Zakariya ibn Yahya al-Saji: Weak in Hadith
Sulayman ibn Dawood al-Tayalisi: The Imam Hafs does not narrate anything from him
Muhammad ibn Isma'il al-Bukhari: They criticize him
Yahya ibn Ma'in: He is nothing
Yazid ibn Harun al-Ayli: He is alright