Stromer doesn't have a complete list of error codes on their website; however, CURR implies something to do with the current. Researched several online blogs on the Stromers and there seem to be 2 common problems: not connecting the charger to the battery & wall socket in the proper order, so the battery isn't charging correctly or at all and second, a missing spacer between the freewheel and the frame which allows the smallest sprocket to rub on the frame. This small drag on a pretty good hill could cause an overload with the motor trying to draw too much current in order to power up the hill. If this is the case, you will need that spacer; however, there may have been damage to the motor. Make sure to disconnect and reconnect those motor connector wires; don't just examine. Sometimes a static charge remains that is dissipated when the wires are disconnected and allows the system to reset. If you are missing the freewheel spacer, you will still need to replace that to prevent future issues with the motor or damage to your frame.