Error msgs after exporting google calendar into iCal

I tried exporting google calendar into my iCal and now I keep getting the following message constantly:

Access to “Calendar note" - XXXXX” in “Personal” in account “iCloud” is not permitted. The server responded: “403” to operation CalDAVWriteEntityQueueab

I respond by selecting "Revert to Server" but as I think ther are thousands of entries (I seem to be getting dates from 3 years ago at least)....is there an easier way to deal with this prob??

Janis