Final answer:
The default period of the duration of the assignor's warranty of the debtor's solvency depends on the jurisdiction and circumstances. It usually lasts for a reasonable period of time.
Step-by-step explanation:
The default period of the duration of the assignor's warranty of the debtor's solvency, when the assignor was in good faith, can vary depending on the jurisdiction and the specific circumstances of the case. In general, if the assignor had no reason to doubt the debtor's solvency at the time of the assignment, the warranty would typically last for a reasonable period of time, allowing the assignee to collect the assigned debts from the debtor.