I keep getting the following error message
Access to “Raymond Furst” in “Calendar” in account “iCloud” is not permitted.
The server responded:
“403”
to operation CalDAVWriteEntityQueueableOperation.
iMac (21.5-inch Mid 2011), OS X Mavericks (10.9.2)
I have this question too since installing Yosemite. It comes up with messages from a certain machine. All others are accepted without a problem.