To fix the windows defender message, just uninstall it and re-download the latest version - it's very common and happens to the earlier installs expiring at the start of the year.
OE6 is actually not opening. It was Dr Watson Debugger that was causing the programm to "freeze". When Dr Watson is removed from the equasion the OE6 just does not open.
I have checked Zone Alarm and OE6 is ticked as an allowed programme.