Thanks Kyle,
Yes, the new Cassiopeia child style method was the culprit. The problem comes from the Colour Settings / Body Text Colour. I have now rgb(187, 175, 175) in that field and that shows the check box with that color and checkmark as white. I'll figure out another color scheme that users will like.
This is going to create all sorts of problems until all extensions align to the new child template method.
Thanks again.
