The ladder in dreams denotes how secure we feel in moving from one situation to another. We may need to make a considerable effort to reach a goal or take an opportunity. Often this dream occurs during career changes and so has obvious connotations.
If the rungs are broken we can expect difficulty.
If someone else is carrying the ladder it could suggest that another person, perhaps a manager or colleague, has a part to play in our progression. You might like to consult the entry for levels / layers for additional clarification.