My two relatively new to me Ming Aralias keep losing leaves despite the added humidifier I have provided. These leaves are not necessarily yellow. They are inside - winter in South Carolina.

A picture or 3 would be helpful.
It is very likely reacting to the lower light levels of winter by loosing leaves.
Remember that with shorter days, weaker light, and lower temperatures they will need LESS water. Also, fewer leaves means they need less.

Here's 2 pics of the Ming. Still rather full, only had the plant about 4-6 weeks. Everyday I can remove a loose leaf segment.

Get them right into your sunniest window for the winter. They are not low-light plants.