My MacBookPro doesn’t have wired Ethernet connects, and transferring gigabit files via WiFi takes forever.

So I purchased an Ethernet adapter to the Thunderbolt connector.

With El Capitan (or earlier MacOS software update) required that you needed to create a new location and re-add the Thunderbolt device. So I looked in the the settings and found in the /Library/Preferences/SystemConfiguration/ folder the NetworkInterfaces.plist settings for older Thuderbolt adaptors listed these (obviously external devices) in Dictionary item of “IOBuiltin” to “YES”. Sometimes software developers just have to fix the settings at the expense of ease of use.