13 Replies Latest reply: Jul 9, 2013 7:03 AM by nevoba
mav2 Level 1 Level 1

Environment - Exchange 2007


Ever since upgrading to Mountain Lion iCal intermittently gives error "ical add invitees not recognized by the server", when this happens several duplicate drafts are created in the Mail appplication and I have to manually delete them.  There seems to be no particular pattern or reason for certain calendar appointments to behave this way but I was hoping the 10.8.1 update would resolve this but it has not.


Any ideas?

iMac, OS X Mountain Lion (10.8.1)
  • xs ebbe Level 1 Level 1

    I've got exactly the same problem.

    My MacBook is connected to an exchange-server (domainfactory hosted exchange) and this issue only shows up with elements created on Microsoft Outlook, invitees or not. The only workaround I've found so far is deleting the calendar entries in iCal and recreating them in iCal.

    Almost as annoying as all the drafts is getting reminders every minute, even if there are no set reminders.


    Let's hope for 10.8.2.

  • David Pakman Level 1 Level 1

    I am having the same problem. No issues with OX X 10.7.x or currently with iOS 5.x but upon upgrading to 10.8 and 10.8.1, iCal reports constant errors connecting to exchange server, including the " invitees not recognized" error and also "Exchange can't save the event to the exchange server" errors. Please address, Apple.


    Here is the console output:


    9/8/12 1:01:53.892 PM CalendarAgent[34024]: [com.apple.calendar.store.log.exchange.queue] [error = Error Domain=CalExchangeErrorDomain Code=-19 "“Breakfast with Michael Zimbalist” had invitees not recognized by the server." UserInfo=0x7fcb21ca7290 {NSLocalizedFailureReason=You entered an invitee that wasn’t recognized by the server., CalFailedOperationKey=<CalExchangeUpdateCalendarItemOperation: 0x7fcb25525940>, NSLocalizedDescription=“Breakfast with Michael Zimbalist” had invitees not recognized by the server.}]




    9/8/12 1:01:54.109 PM CalendarAgent[34024]: [com.apple.calendar.store.log.exchange.queue] [error = Error Domain=CalExchangeErrorDomain Code=-4 "Calendar can’t save the event “Breakfast with Michael Zimbalist” to the Exchange server." UserInfo=0x7fcb233e9870 {NSLocalizedFailureReason=The account "Venrock" currently can’t be modified. To discard your changes and continue using the version of your calendars that’s on the server, click Revert to Server., CalFailedOperationKey=<CalExchangeUpdateCalendarItemOperation: 0x7fcb23298340>, NSLocalizedDescription=Calendar can’t save the event “Breakfast with Michael Zimbalist” to the Exchange server.}]

  • rootdr Level 1 Level 1


    Need a solution to this Apple!

  • xs ebbe Level 1 Level 1

    I've been at an Apple Store last weekend because of a hardware problem and I've been talking to the genius about this issue. He told me that this is something he gets lots of complaints about, among several other Mountain-Lion-issues. The guy hopes for a solution in 10.8.2, just like the rest of us.

  • rootdr Level 1 Level 1

    I am in the ML 10.8.2 seed and can confirm it does NOT resolve the issue unfortunately.

  • Drillbitmarketer Level 1 Level 1

    I found a thread yesterday that solved my problem, but I can't find it today to reference. In essense, ML is moving towards OS based settings, not application based settings with Calendar. I deleted my exchange account from calender, then went to system preferences, mail contacts and calendars and checked calendar under the exchange account. That was 24 hours ago and the error has not come back. Hope this helps.

  • mav2 Level 1 Level 1

    Anybody notice any improvement with latest mountain lion update released last week?

  • TotoTron Level 1 Level 1

    Thanks drillbitmarketer, that worked for me also.

  • xs ebbe Level 1 Level 1

    My thanks to Drillbitmarketer, too. Your solution seems to work for me.

    Additionally I had to delete and recreate my exchange account in the system preferences.



    All the latest mountain lion updates didn't change anything about this issue.

  • Ohmster Level 1 Level 1

    Yup. Worked for me when like xs ebbe, I deleted and then added back the Exchange account.

  • mav2 Level 1 Level 1

    When I check Calendar under system preferences it's already checked (have not removed account from iCal yet).

  • xs ebbe Level 1 Level 1

    After a few weeks I have to say that it doesn't always work. There are still some appointments with unknown invitees. It happens less frequently, but the issue is not yet completely solved. The last time it happened the item was created on my iPhone (still on iOS 5.1.1 because of Apple Maps and iTunes Match).

  • nevoba Level 1 Level 1

    I just had this issue and finally resolved it. Just find all of your  apple devices that connect to the exchange calendar and make sure that  all of the alerts are set to "none" this includes mobile devices,  desktops and laptops. For some reason whenever you have "All Day  Events:" alerts set to "1 day before (9AM)" the device will put a  reminder in the exchange server calendar, which then causes other apple  devices to convert the event into a meeting without any invitees. Don't  ask my why this happens, i've already submitted a bug report to apple  and no response yet. This is totally reproduceable.