Open the System Settings App and navigate to Privacy & Security.
Select Privacy & Security and scroll down in the right-hand pane all the way to the bottom, to the option called Profiles.
Click it.
Locate the profile named 802.1X (GSG), select it by clicking on it, then press the little minus (-) icon at the bottom of the list.
To remove the old profile, you will have to enter your Mac's username and password (or Touch ID).
After entering your credentials, the old profile will be removed from your Mac.
You can now attempt to install the 802.1X WiFi profile on your Mac again.