I agree, your plant is
Dwarf Umbrella Tree (Heptapleurum arboricola 'Variegata')
My first thought was that your plant is likely needing
more light and
less water, especially at this time of year but if you've been growing it, without issues for 14 years, something might have changed recently to cause it's decline.
How long ago did you last repot it? Are there drainage holes at the bottom of the pot to allow for excess water to leave the soil? Did you possibly place pebbles/rocks or broken pieces of crock in the bottom of the container when you repotted? For some reason, that method of potting has come back into style but it's never a good idea because it causes issues with proper soil aeration and drainage, leading to root rot.
Test for moisture by sticking your finger an inch or two down into the soil; if it feels wet, it's still likely quite wet at root level and you will need to adjust your watering routine to allow the soil to dry longer before adding more water.
I've propagated many Schefflera by pruning the stems and sticking them in very small pots of moist soil but I usually do it in the warmer months.