Fixed…
I placed this in the Enfold general styling CSS section. However, after saving it, I didn’t notice any change on the page. Should I have done something different?
Sure thing, really appreciate the help and feed back. After a bit more digging I suspect it may have been the Yoast plugin based on the link listed below. I disabled the plugin, updated again, and then activated. It would seem to be better, but would like a second opinion.
https://wordpress.org/support/topic/error-warning-class-_php_incomplete_class-has-no-unserializer/
Sorry for late response, however, really appreciate your time. I will give this a try to see what I come up with!