Tag: Outlook

ActiveSync EAS Broken in M365 Outlook

Update: This issue is fixed in Outlook Desktop Version 2402 Build 17328.20068 and higher

Ran into an issue with an update to M365 Apps where ActiveSync FolderSync breaks with connection resets on Outlook version 16.0.17126.20182.

To find out the build version in Outlook, go to File > Account

To find out the build version from a command line:

reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\Configuration /v ClientVersionToReport

Microsoft is investigating and has issued the following workaround: https://support.microsoft.com/en-us/office/outlook-desktop-exchange-activesync-connections-stopped-working-in-version-2401-da2dc0dd-297e-48ba-b6d9-ab18f5d522fc

The command to downgrade the M365 Apps:

cd %programfiles%\Common Files\Microsoft Shared\ClickToRun
officec2rclient.exe /update user updatetoversion=16.0.17126.20132

MSTeams Fastconnect Outlook Addin Disabled

Outlook keeps disabling the MSTeams Fastconnect addin which removes Teams meeting functionality from the Outlook Calendar view. To restore this, I used the following steps.

  1. Launch RegEdit.exe
  2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins
  3. Verify TeamsAddin.FastConnect exists.
  4. Within TeamsAddin.FastConnect, verify LoadBehavior exists and is set to 3.
  5. If LoadBehavior has a value other than 3, change it to 3 and restart Outlook.
    For more details about how to troubleshoot this issue, you can refer to:
    https://learn.microsoft.com/en-us/microsoftteams/teams-add-in-for-outlook#troubleshooting

If the add-in has been disabled, you can try to follow these steps to prevent it:

  1. Launch RegEdit.exe
  2. Go to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Resiliency
  3. Delete the DisabledItem if there is.