Sharepoint Calendar not updated when new items are added to Outlook Calendar RRS feed

  • Question

  • We have a Calendar on Sharepoint.  From this calendar, users are able to Sync with Outlook.  We primarily have one user who updates this Calendar.  This user has synced the Sharepoint Calendar with Outlook.  From Outlook they update the calendar on Sharepoint, by adding events to it in Outlook.  Every 3-5 months we run into this issue where when this one user adds an event, the event will not update on the Sharepoint Calendar.  The event successfully adds to the same calendar in Outlook, but shows up as "Modifed by Unknown" instead of displaying her name.  We run a terminal server environment.  I have pointed this user to another TS with no luck.  Others are able to add events to the same calendar w/o any problems.  This user is able to add items to the Sharepoint Calendar, and they show up fine.  When this is done, they also show up successfully in her Outlook Calendar.  There seems to be a communication issue specifically with this one user, from Outlook to Sharepoint.  I've pulled the WSSSyncying Logs, but am not familiar with what I'm looking at.  Any ideas?

    Monday, February 14, 2011 8:36 PM

All replies

  • Hi ChristopherPC,


    If I understand correctly, your problem is the SharePoint Calendar doesn’t synchronize with Outlook Calendar after the user added an new item to Outlook Calendar. If it is so, the problem may lie on corrupt entries. If you go to your SharePoint Site and view the calendar you are having trouble with. Export using access and arrange by name, you will probably find some blank entries, if you delete these then close access all should be fine.


    You can also try to remove the calendar and re-add it using the Account Settings in Outlook:

    1.       Tools -> Account Options -> SharePoint Lists

    2.       Select the SharePoint calendar and click remove

    3.       Then go to the calendar site and connect to Outlook

    Thanks & Regards,

    Peng Lei

    Tuesday, February 15, 2011 2:40 AM
  • Peng Lei,

    You are correct.  However, when I export the Sharepoint Calendar into Access I do not get a column for "name".  I do have columns for ID, Start Time, End Time, Recurrence, Workspace, Title, Location, Description, All Day Event and an attachment column.  I'm using Access 2010.  Some noticeable items on the Access export.

    • Some items in the Start Time column have dates and times but some just have dates.  This may be due to the fact that this particular user is now adding events directly to the Sharepoint Calendar instead of adding to their Outlook Calendar
    • The Workspace column is mostly blank, but some fields to contain a "0"
    • Out of the 564 records, 6 of those have nothing in the Title column, or the title column is blank but does contain data in all other fields (except for Location and Description which are blank for all records).

    When I do Export the Sharepoint Calendar to Access, I'm assuming I need to select the option to Link to Sharepoint so that any changes that are made in Access are also made in the Sharepoint Calendar?

    Also, I have removed the Sharepoint Calendar from their Outlook and this does resolve the problem short-term.  Then 3-5 months later it reoccurs.

    Wednesday, February 16, 2011 8:25 PM
  • Disregard the first bullet point above.  I now see that some events were all day events (thus negating times) and some were for specific times.  I deleted all events that had nothing in the Title field, saved it back to the Sharepoint Calendar and had this one particular user attempt to add an event to their Outlook calendar which is connected to the Sharepoint calendar.  This event showed up again as "Modified by Unknown" and did not update on the Sharepoint calendar. 
    Friday, February 18, 2011 9:17 PM
  • This issue has cropped up again for just this one user yet again.  Approximately 63 days ago is when the issue last happened and seems to stick to this schedule, every 60 days.  This is the only employee who adds content to this calendar via Outlook.

    Even more bizarre, employee was able to add content earlier today w/o any problems 9:58am.  She tried adding items at 11:48 and they showed up as "Last Modified by Unknown".  When exporting the data from the Sharepoint calendar that is linked to her Outlook calendar, I did find 15-20 blank entries which I deleted.  What can cause these blank entries (user error or corrupt Outlook profile)?

    Tuesday, April 19, 2011 6:37 PM
  • I have a single user with the same exact problem and so far no answer as to what causes it. Did you ever find a solution to this, ChristopherPC?

    I think this is something directly related to "Last Modified by Unknown User". All previous appointments specify the user. The appointments that Identy "Unknown" are the only ones that are not showing up on Sharepoint Calendar.

    Does anyone have any other suggestion on how to fix this?


    Wednesday, August 24, 2011 7:24 PM
  • Scott,

    I tried exporting the data from the Sharepoint Calendar to Access, then sorted the title column to find any empty or blank entries.  After deleting those, the issue still came back after several weeks.  Our Sharepoint Calendar did have several years worth of information in it, so I did go back and I cleared out all the previous years, I think there were 3 or 4 years worth of stuff I deleted off the Sharepoint Calendar.  I downloaded a copy of the calendar to Excel, and saved it to a shared location of users who did add content to the calendar should they need to reference anything.  I did this approximately end of July, so far the issue has not reoccured.  With that said though, sometimes it would be several months between this issue arising again.

    Thursday, August 25, 2011 1:43 PM
  • Thanks Christopher!

    I was able to finally get her going. I removed .ost file from her system, rebuilt profile.  Removed the Sharepoint Calendar from her Outlook. After a reboot, I added the Shared calendar back and now everthing is working as it should.

    Bad thing is, I still don't know what caused it to break, and I don't guess anyone else does either.


    Thursday, August 25, 2011 8:50 PM
  • Hi  ChristopherPC

    I am having this same problem but we only have about 6 months worth of information on in... are you all still having this problem?

    Tuesday, December 13, 2011 6:21 PM
  • Just wondering if this solved ur problems
    Tuesday, December 13, 2011 6:22 PM
  • Just wondering if this solved ur problems

    Funny, I had our same user having this issue contact me yesterday with a reoccurence.  Unlike ScottTPC and his issue, we're in a Termial Server environment so deleting the .ost file isn't an option.  No fix as of yet other than Removing the Sharepoint Calendar from Data File Management in Outlook, deleting the Calendar from their Calendars in Outlook and re-syncing.  This will fix for 3 months or so until it appears again.
    Tuesday, December 13, 2011 6:26 PM
  • I just discovered a client with the same issue.  Since 2/23 none of her Outlook posts are syncing to SP.

    Common to all are the words "Last Modified by Unknown..." on the bottom right of the appointment.

    Deleting and Reconnecting the list to OL does nothing.  Deleting all entries with blank subject line did not help.

    I'm wondering about the All Day Events.  SP handles them differently by adding times whereas I don't think OL does.

    Any thoughts?

    Thursday, March 8, 2012 8:58 PM
  • I just found this and worked for me.

    "A problem I recently came across with is having a calendar on a SharePoint site connected to the Outlook, however, changes made in the Outlook did not synchronize with the site’s calendar. After searching a bit on the net there was no solution to fix the problem, so here it is!

    The problem probably occurs due to a bad appointment in Outlook’s SharePoint lists PST file. To fix this you need 2 things:

    1. Find the SharePoint lists PST file location (can be done by file -> configure -> Outlook files)
    2. Close all Outlook windows (i.e. processes) and using the ScanPST program (can be found in C:\Program Files\Microsoft Office\Office14\SCANPST.exe, on any version of Outlook) search for that PST file, scan it for errors and fix it!

    This little program fixes the bad appointments, and when you’ll open Outlook again – all the changes will be synchronized.

    Happy fixing for you all

    Wednesday, July 3, 2013 7:36 PM
  • Check the all items list in SP for a record containing no subject/title.  Outlook will hang or stop sync if required info is missing.
    Wednesday, July 3, 2013 7:58 PM
  •  Users in my company are reporting calendar issues with Outlook synch. I started to investigate and realize when you enter by IE to the calendar page it seems empty on the actual Month, when you change month (one up or down) the information are appearing and when you go back to the actual it is solved. This is curious and I think it is linked to Sync issue with Outlook.

    Any Idea?
    Wednesday, August 2, 2017 3:25 PM