Environment: Outlook 2010 v14.0.7106.5003 (cached mode) / Exchange 2010 SP3+RU4 (v14.03.0174.001)

We are following this guideline to propose a new meeting time: http://office.microsoft.com/en-us/outlook-help/propose-accept-or-decline-a-new-meeting-time-HP010356518.aspx

User1 sends a meeting invitation (monday 10:00-10:30) to user2. The appointment appears at user2 calendar with status "tentative". So long, so good.
User2 clicks on "Decline and Propose New Time" and selects a new time (monday 11:00-11:30).

Result: The appointment is removed from user2 calendar instead of being moved to the proposed time. User1 receives a notification (Subject: "New time proposed: ... ") with the information "appointment declined" but there is no option to accept the new time and also no hint about the new time.

If found a lot of posts with the same issue but no solutions...

Any ideas?

Hi,

Do the users have 3rd-party add-ins installed?

Let's try running Outlook in Safe Mode:

Press Win + R and type outlook.exe /safe in the blank box, then press Enter.

Test if this issue persists when testing in Outlook Safe Mode, if theres no problem in Safe Mode, disable the suspicious add-ins to verify which add-ins caused this issue.

Regards,

Melon Chen
TechNet Community Support

Do the users have 3rd-party add-ins installed?

Let's try running Outlook in Safe Mode:

Press Win + R and type outlook.exe /safe in the blank box, then press Enter.

Test if this issue persists when testing in Outlook Safe Mode, if theres no problem in Safe Mode, disable the suspicious add-ins to verify which add-ins caused this issue.

There are no 3rd Party Add-ins installed. The same problem occurs in safe mode!

The problem exists on all Clients within this AD. I also manage another AD where the problem doesn't occur. Outlook & Exchange versions are the same...

Any ideas?

Problem vanished! I don't know if it was fixed by a Windows update or due to a server reboot...

• Marked as answer by Daniel-Hoegele Wednesday, March 19, 2014 1:21 PM
• Unmarked as answer by Daniel-Hoegele 1 hour 16 minutes ago

Problem vanished! I don't know if it was fixed by a Windows update or due to a server reboot...

• Marked as answer by Daniel-Hoegele Wednesday, March 19, 2014 1:21 PM
• Unmarked as answer by Daniel-Hoegele Tuesday, February 24, 2015 10:38 AM

Almost exactly one year later the same problem reoccured and I still have no idea why it vanished last time. Maybe it will vanish again after 4 weeks, but I wont bet on it.

Therefore: Any ideas how to fix this?

Exchange 2010 is up to date, same applies to Outlook 2010 clients. Server has already been restarted.

Thanks

Daniel