Umbrella Plant Question

by Karen
(Vancouver, BC, Canada)

Hello There,
I have a mature, indoor, umbrella plant (non-variegated)that is producing excessive sap, which drips all over my kitchen floor. Needless to say, this sticky stuff is a real pain to clean up. I have had this plant for more than 10 years, and have kept it in the same location the whole time, but this "sapping" has only been occurring during the past year or so.

I'm wondering if someone has any idea what might be causing this and what I can do about it. I welcome any feedback anybody might have to offer.