If a Sheikh or a website issues an incorrect fatwa, and the questioner abides by it, does the questioner bear responsibility or sin, or the one who issued the fatwa, or both of them?

The layman must seek fatwa from one whose knowledge and piety he trusts among the people of knowledge, and act upon their fatwa, for Allah Almighty says: "So ask the people of the message if you do not know." However, it is not permissible for him to act upon a fatwa if he knows that the matter is, in reality, contrary to it, as Ibn al-Qayyim said: "It is not permissible to act merely upon the fatwa of a mufti if one's soul is not at ease," and due to the Prophet's (peace be upon him) saying: "Consult your heart, even if people give you fatwa and give you fatwa." So, the mufti's fatwa does not absolve the questioner from Allah if he knows that the matter is contrary to what he was given fatwa about, and this also applies to a judge's ruling. If the questioner loses trust and reassurance due to the mufti, he must ask someone else until he feels at ease. And whoever issues a fatwa without knowledge, being unqualified for fatwa, is sinful.