1) violence or attack - physical,
3) violence - verbal and emotional
4) dishonesty of any sort
5) lack of understanding, caring, and mutual communication.
The first item is dangerous - often attacks escalate, especially when the person being attacked considers leaving or tries to leave. Safety is first, and rescuing the marriage is challenging, and may be best not to do it.
Infidelity is very difficult to heal, but some marriages, with effort on both sides, have healed through it.
Verbal violence and dishonesty can be healed, but only if the person doing it wants to change, and both people are committed to the relationship.
If you get past all of those, then a marriage - with or without children - is still an awful lot of work - absolutely wonderful work, in my opinion - as we learn to trust, nurture, and grow our love for one another, our families, and the world.