At least one embodiment may provide a remote server that can determine occurrence of an abnormal condition in a power transmission system without using a threshold value in advance. There may be provided a remote server that receives operating and non-operating information of a working unit, information on a working date, information on a traveling speed, and information on a load factor of an engine, respectively from a combine harvester. The remote server calculates for each predetermined period an average of the engine load factor while the traveling speed is at or above a predetermined traveling speed with all working units in non-operation. If the average during a predetermined period is in a status of a predetermined difference from the average up to the predetermined period, the remote server determines that a moving power transmission mechanism of a traveling system of the combine harvester is in an abnormal condition.