Access denied. You do not have permission to perform this action or access this resource.

I have one list for which one user , i have granted Edit permission,

but whenever user try to edit , he can see edit tab, he can change values, but when he click on Save button on edit mode, he will get following error

Access denied. You do not have permission to perform this action or access this resource.

same error he will get when he add new items and try to save

what is reason? user already have edit permission on list