I have calendar events duplicating hundreds of times

Microsoft - I'm having a similar issue. I understand you're a billion dollar corporation; but we small business owners (which I am part of 7 companies) use all of your business suite & pay accordingly. I don't want a bogus article that doesn't rectify the issue everyone in this thread has. Do some customer support, reach out directly, and fix this issue of your product. Keep in mind these breaks cost us so much time and money.

No easy answer, I had to get a MS engineer to fix this. He used this tool MFCMAPI.x64.exe.24.0.24100.06 which you can download but I don't recall which site.

I wouldn't try it myself as you could cause a lot of damage with it.

The other option is to set Out look to offline and delete each one at a time. Then delete them from your outbox before they are sent to recipients.

I have exactly the same issue. All my devices are running really slow. I have more the 3814 duplicate outlook agenda items. It's impossible to delete them by hand. All the ivited person are getting a cancellation when I delete an item. And Outlook keep adding more duplicate items when I remove them.

How do I fix this issue?

I'm using Outlook Version 2405 (build 17628.20110 click-and-run).

My meeting replicated 2070 times. I tried deleting manually but each person gets an email for meeting cancellation.

Is there a way to delete these without emailing all attendees?

thanks

https://support.microsoft.com/en-au/office/outlook-shows-conflict-errors-when-updating-or-cancelling-meetings-69c26227-40ef-4377-8f12-1749fcaad2ad
Solution is here. It worked for me right away

STATUS: WORKAROUND

The Outlook Team is investigating this issue. In the meantime, please use the following workarounds:

Workaround 1:

To mitigate the issue, you can use the Clear Offline Items for your calendar. This step clears the calendar items in the Outlook store (OST) on your local machine.   

To clear offline Calendar items, follow these steps: 

Open the Calendar pane in Outlook, and right-click the Calendar folder.

Select Properties.

On the General tab, select Clear Offline Items.

Select OK.

After you clear offline items, Outlook will re-sync the calendar and repopulate your calendar folder with the calendar items on the server. 

Workaround 2:  

Make the meeting updates in Outlook Web Access (OWA) or use New Outlook. The conflict does not occur when updating or cancelling the meeting in OWA or New Outlook.