Q.Yellow leaves and brown spots on jade plant
I have a fairly large jade plant that recently has been getting a lot of yellow leaves and then they drop off. Other leaves have dark brown spots in the center. What can I do to prevent any more leaves from turning yellow or dark brown spots on the leaves? Also, some leaves look like something has been chewing on the edges.

Certified GKH Gardening Expert
It sounds like you may have over watered the plant, which could have led to a fungal issue or root rot. This article will help determine if root rot is a problem: https://www.gardeningknowhow.com/plant-problems/disease/treating-root-rot-gardening-tips-for-housplants.htm
If the roots look healthy, it is likely a fungal infection. Treating with neem oil or another suitable fungicide shouls help with this. Keep in mind that Jade plants are succulents and they need very little water. They should be allowed to dry out between waterings.