Update, I ran System File Checker, which fixed some corrupt files. I then uninstalled, downloaded and reinstalled the Universal Installer. I rebooted, and the Live Update started to run, then an Unhandled exception error came up.
************** Exception Text **************
System.IO.FileLoadException: Could not load file or assembly 'QlmLicenseLib, Version=16.0.22168.1, Culture=neutral, PublicKeyToken=9c65e32c060523a1' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
File name: 'QlmLicenseLib, Version=16.0.22168.1, Culture=neutral, PublicKeyToken=9c65e32c060523a1'