in your translation (when passing with the mouse on the word) it's written 'other' rather than 'others'
But since 'andere' (-> haben) is plural in this sentence, 'others' is correct.
Shouldn't it be anderen then since that means "others?"
No: andere is the plural form in both nominative and accusative cases:
I wrote "Others have this." Earlier in this lesson they showed that "this" and "that" are both correct translation of "das". Which was the error?
shouldnt it be "Anderen haben das".