1 pointWindows Defender is the standard anti-virus program that comes with Windows 10. It will show up as a shield icon in the trayicon area. Double-click on it, select "Virus & threat protection => Virus & threat protection settings => Manage settings => Exclusions => Manage exclusions". Add the RTI_Builder folder (usually in the root directory on the C- drive). This should fix the problems. You may need to reinstall RTIBuilder.