Outlook Desktop crashes sending a meeting invite that includes a Loop component

Last Updated: September 6, 2023

ISSUE

When you send a meeting invite that includes a Loop component, Outlook crashes when you click Send. This issue happens after updating to Version 2307 Build 16626.20170. 

In the Application Event Log the crash event will match the specifics below: 

Faulting application name: OUTLOOK.EXE, version: 16.0.16626.20170, time stamp: 0x64cc6089 
Faulting module name: mso20win32client.dll, version: 0.0.0.0, time stamp: 0x64cc5e7b 
Exception code: 0x004c620e 
Fault offset: 0x000000000027b5bd 
Faulting process id: 0x1894 
Faulting application start time: 0x01d9cafedceb4b72 
Faulting application path: C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE 
Faulting module path: C:\Program Files\Common Files\Microsoft Shared\Office16\mso20win32client.dll 

STATUS: FIXED

This issue is initially fixed in build 16904.10000 which will go to Current Channel in late October 2023. See the Update History page for build release status. To check the status when the fixed build will go to the Beta Channel or Current Channel Preview see the Update History for Office Beta Channel.  

Since the latest update is a security update it is not recommended to revert the build. If you urgently need to workaround the issue you can revert to the prior build that worked.

1. Open a Command Prompt in Administrator context.

2. Type or paste the two commands into the Command Prompt window and press Enter after each:

   • cd %programfiles%\Common Files\Microsoft Shared\ClickToRun

   • officec2rclient.exe /update user updatetoversion=16.0.16626.20134

The builds to revert are taken from the Update History page, Update history for Microsoft 365 Apps (listed by date). Beta and Current Channel builds are here, Update history for Office Beta Channel.

Additional Resources

Use Loop components in Outlook