Import .vcs file into google calendar
I had the same problem yesterday when I was moving many .vcs files from my old mobile to Google Calendar. I found a solution when I was removing some lines from these files. In my case it was the line which begins with "RRULE", e.g.:
RRULE:YM1 #0
Maybe that line cause error in your case too. All I needed was to remove that line.
Try changing "End" to "END" in the file and saving as a .ics. Then do your import steps from above.
This little trick lets you save United Airlines Reservation and other .vcs files to Google Calendar.