Changing fields to property is a breaking change under what scenarios?

Question

While reading Jon Skeet\'s article on fields vs properties he mentions that changing fields to properties is a breaking change.

I would like to understand the common

Answer 1

In Windows Forms at least, you can only databind things like DataGridViewColumns to properties on your business objects, not fields. So if your class was being used as a DataSource for a grid, its properties changing to fields would result in some new bugs for the grid owner.