" Processed 4675 events.

Successfully imported one event.

Failed to import events: Some of the events in this file were not imported because you had imported them to Google Calendar before. Other events in this file have been imported.."

I had no problem importing into a secondary calendar though. I contacted Google support.The tech edited your file, and it started working with the primary calendar. He mentioned something that the file was not up to the standard, and he had to remove some code out of the file. On my question he mentioned something about "event ID" being wrong. Also he removed word "import" or "important". Something else was also done. I have both files. If you are interested, I can attached them to an email. Each of them is close to 2 Mb.