The word(s) "error" appears 50 time(s) in 50 verse(s) in Quran in Abdullah Yusuf Ali translation.

(41) Is one whose heart Allah has opened to Islam, so that he has received Enlightenment from Allah, (no better than one hard-hearted)? Woe to those whose hearts are hardened against celebrating the praises of Allah! they are manifestly wandering (in error)!

(42) Now, when he came to them in Truth, from Us, they said, "Slay the sons of those who believe with him, and keep alive their females," but the plots of Unbelievers (end) in nothing but errors (and delusions)!...

(43) They will say: "Did there not come to you your messengers with Clear Signs?" They will say, "Yes". They will reply, "Then pray (as ye like)! But the prayer of those without Faith is nothing but (futile wandering) in (mazes of) error!"

(44) Canst thou then make the deaf to hear, or give direction to the blind or to such as (wander) in manifest error?

(45) "If any does not hearken to the one who invites (us) to Allah, he cannot frustrate (Allah's Plan) on earth, and no protectors can he have besides Allah: such men (wander) in manifest error."

(46) So leave them alone until they encounter that Day of theirs, wherein they shall (perforce) swoon (with terror),-

(47) It is He Who got out the Unbelievers among the People of the Book from their homes at the first gathering (of the forces). Little did ye think that they would get out: And they thought that their fortresses would defend them from Allah! But the (Wrath of) Allah came to them from quarters from which they little expected (it), and cast terror into their hearts, so that they destroyed their dwellings by their own hands and the hands of the Believers, take warning, then, O ye with eyes (to see)!

(48) Of a truth ye are stronger (than they) because of the terror in their hearts, (sent) by Allah. This is because they are men devoid of understanding.

(49) It is He Who has sent amongst the Unlettered a messenger from among themselves, to rehearse to them His Signs, to sanctify them, and to instruct them in Scripture and Wisdom,- although they had been, before, in manifest error;-

(50) Say: "He is (Allah) Most Gracious: We have believed in Him, and on Him have we put our trust: So, soon will ye know which (of us) it is that is in manifest error."