Appointment showing as tentative even after accepting it multiple times

Question

I am experiencing this weird issue with Outlook 2013: I have several appointments in my calendar, but no matter how many times I accept one of them (this happens to two appointments actually, the others seem to work just fine) it just goes back to Tentative after a few seconds.

It shows correctly on iOS however, which leads me to think that the issue might indeed be on the Outlook side. Any thoughts?

Some more information

I am using Outlook 2013 on Windows 8 and the default calendar app on iOS. Every action I do is performed in Outlook, I use the phone only to view information and not to act on appointments.

Behavior in Outlook: the appointment initially shows as tentative in my calendar before accepting it (correct behavior), then I accept it, it shows as accepted for a while before turning back to tentative (after a few seconds).

On iOS: the appointment is correctly shown as accepted.

Answer 1

This is not exactly a solution, just what I have found out about the problem.

As far as I can tell, this bug exists in Outlook since a long time. For example, I have found a reference to it from 2009 in the thread Exchange Calendar Invites Reverting to Tentative After Accepting:

We are using Exchange 2003 with the latest serivce packs, clients have Vista sp2 with Outlook 2007 sp1. The affected users do not have delegates. As long as the iPhone is not syncing the calendar, the meetings show as busy. When iPhone calendar is on, meetings revert to tentative within a few minutes. None of the solutions presented in any of these forums have worked.

I have not been able to find anybody who claimed to have solved this problem, except by disabling the option of introducing invites into the calendar as tentative.

However, the above text seems to hint that it is the iPhone resync that actually deranges the Exchange server.

One explanation is that the bad appointments were loused-up in the Exchange database by the iPhone resync, so that the iPhone shows the status as it understands, while Outlook shows the status as it understands. Thereafter, both iPhone and Outlook just continue to mishandle the appointment.

You could test this theory by trying to see if new appointments can go bad while the iPhone is turned off.

Answer 2

I was/am having the same issue. It only affected some appointments and there did not seem to be any exclusive pattern to the ones affected. I say 'exclusive' because although all affected meetings were recurring, not all recurring meetings were affected. However, I found that if I opened the series and accepted the meeting, it continued to show them as tentative. However, if I opened "just this one" and accepted, it oddly accepted the entire series.

Answer 3

I have found that when I accept a meeting via my iPhone (for my Outlook calendar, in this case, my work calendar), the meeting always shows as TENTATIVE.

A quick fix was: On my iPhone, click on the meeting (from your calendar). This will bring up the EVENT DETAILS. At the bottom, there is a category that says: SHOW AS >

If you click SHOW AS, you can show time as something other than Tentative, like Busy or Free. Once I selected Show As Busy, it automatically synced with my Outlook calendar, and the meeting no longer showed as tentative on my Outlook calendar.