Does a benefactor sin or is his reward diminished if he is unable to renew the orphan’s sponsorship after one year, despite his awareness of its importance for the child?

Sponsoring an orphan holds a great status in the religion, for the one who sponsors an orphan will be a companion to the Prophet, peace and blessings be upon him, in Paradise. The sponsor is the one who nurtures and takes charge of the orphan's affairs in everything that benefits them in their religion and worldly life, including sustenance, clothing, upbringing, and education, not merely the one who spends on them. If someone was spending on an orphan and something prevented them from continuing their expenditure, but they were determined to continue doing so, then it is hoped that they will receive the full reward of the charity, because a sincere intention coupled with possible action, along with a valid excuse, grants its owner the reward of a complete doer.