Umbrella tree house plant
When leaves die from the tip, it often points to root dieback. This could be caused by overwatering or underwatering. Has your watering routine changed? Has the plant experienced any other change in its environment? Keep in mind that plants use less water as the days get shorter and they grow less. Also, air temp is cooler, causing less evaporation from the soil.
Scheffleras do not like it too wet. When actively growing, they should be watered only moderately. Watered to wet all the soil, but letting it dry a lot between waterings. In the winter, only water enough to keep the potting soil from completely drying out.
Could also be disease, but not as likely.