I went to bed, got up, open Calendar on my MacBook Pro to find the same message popped up again. It took about 30 mins for it to disappear only to be replaced by "Couldn't move your calendars to iCloud because an error occurred" message.
I am running Mavericks and I am sure my Internet connection is working fine. Does anyone have the same problem or a solution?
iCloud's Calendar is full of errors and problems for me. The "Couldn't move your calendars to iCloud because an error occurred" is now gone (by itself) but nothing syncs between my Mac's Calendar to iCloud or my iPhone to iCloud.
I tried creating a new event directly on iCloud.com to see whether it pushes to any of my device and got this "This event couldn't be created because of a server error; please try again." error.