Exactly what are you doing, what is happening and what do you expect to happen?

You assertion that none of the export methods work may be the case for you. But not for most folks. So the first thing that needs to occur is to establish exactly what you are doing. Is what you are exporting your calendar stored locally or a network calendar stored on the web? I notice I can not export the US footy calendar that is linked from my google account where it is linked for elsewhere. I can export other calendars