From my mentioned example one reason was cause the user loaded a csv file with incompatible data.
Or cause the user had filled in part two of a task but not part one and then tried to continue with parts of the task that where dependent on filling in part one.
Or the user tried to synchronize orders from the erp system but the erp system would not return any orders.
Or cause the user had filled in part two of a task but not part one and then tried to continue with parts of the task that where dependent on filling in part one.
Or the user tried to synchronize orders from the erp system but the erp system would not return any orders.