The synod bishops cited the challenge of poverty:
49. Here I would also like to mention the situation of families living in dire poverty and great limitations. The problems faced by poor households are often all the more trying. (Relatio Finalis 15)
Pope Francis has a particular example that’s not particularly rare:
For example, if a single mother has to raise a child by herself and needs to leave the child alone at home while she goes to work, the child can grow up exposed to all kind of risks and obstacles to personal growth. In such difficult situations of need, the Church must be particularly concerned to offer understanding, comfort and acceptance, rather than imposing straightaway a set of rules that only lead people to feel judged and abandoned by the very Mother called to show them God’s mercy. Rather than offering the healing power of grace and the light of the Gospel mes- sage, some would “indoctrinate” that message, turning it into “dead stones to be hurled at others”. (Concluding Address of the Fourteenth Ordinary General Assembly of the Synod of Bishops (24 October 2015): L’Osservatore Romano, 26-27 October 2015, p. 13)
A point that needs to be made, but still one that annoys many of us deep in religion, those who would prefer to be right than be merciful.
For your reference, remember that Amoris Laetitia is online here.