If you are having this error with an Excel file saved in SharePoint Online being stuck at “Performing Cleanup” when closing the file, this fix might help you. Also, the file is somehow cached locally and does not update with the current online version of the file. Onedrive reset also does not help.

Empty this folder:

%localappdata%\Microsoft\Office\16.0\OfficeFileCache

This might also help you:

https://www.koskila.net/performing-cleanup-excel-is-stuck-with-an-old-conflicted-file-and-will-never-recover/

This Monday, 13th of January 2025 was a bad day for sysadmins. Outlook and other Microsoft 365 / Office Apps would crash upon start because of a new update pushed by Microsoft. The message says something about react-navis-win32.dll missing. The only fix is to install the December 2024 Updates to fix the issue.

This configuration XML File install the December 2024 updates. Beware: This configuration is for Windows Server 2016 RDS and note that automatic updates are disabled.

<Configuration ID="e2abcd00-6229-40cc-be2d-e3a8ff5efb34">
  <Add OfficeClientEdition="32" Channel="Broad">
    <Product ID="O365BusinessRetail">
      <Language ID="de-de" />
      <Version ID="16.0.17328.20670"/>
      <ExcludeApp ID="Groove" />
      <ExcludeApp ID="Lync" />
      <ExcludeApp ID="OneDrive" />
      <ExcludeApp ID="Teams" />
    </Product>
  </Add>
  <Property Name="SharedComputerLicensing" Value="1" />
  <Property Name="SCLCacheOverride" Value="0" />
  <Property Name="AUTOACTIVATE" Value="0" />
  <Property Name="FORCEAPPSHUTDOWN" Value="FALSE" />
  <Property Name="DeviceBasedLicensing" Value="0" />
  <Updates Enabled="FALSE" />
  <RemoveMSI />
  <Display Level="None" AcceptEULA="TRUE" />
</Configuration>

To download data hit setup.exe /download configuration.xml

To install execute setup.exe /configure configuration.xml

References:

https://borncity.com/win/2025/01/13/microsoft-outlook-365-or-other-ms-365-apps-are-dropping-suddenly-errors/

These 3 registry keys will help you block the rollout of Outlook NEW which is like a lot of Microsoft products a half baked solution that is being pushed by force to push something new.

This key hides the “Try new Outlook” toggle in the top right:

HKEY_CURRENT_USER
Software\Microsoft\Office\16.0\Outlook\Options\General
name HideNewOutlookToggle
type REG_DWORD
data 0x1 (1)

These key disables migration to new Outlook:

HKEY_CURRENT_USER
Software\Microsoft\Office\16.0\Outlook\Options\General
name DoNewOutlookAutoMigration
type REG_DWORD
data 0x0 (0)

HKEY_CURRENT_USER
Software\Policies\Microsoft\office\16.0\outlook\preferences
name NewOutlookMigrationUserSetting
type REG_DWORD
data 0x0 (0)

As a follow up to my last article regarding Microsoft Teams NEW Addin missing in Outlook https://www.ajni.it/2024/03/microsoft-teams-lightweight-teams-meeting-addin-in-outlook-missing/, this script might help you if there are still some issues especially on Terminal Services/RDS 2019/2022.

This script registers Microsoft.Teams.Addin.Loader.dll as the current user, so it has to run at logon.

if (-not ($NewTeamsPackageVersion = (Get-AppxPackage -Name MSTeams).Version)) {
Write-Host "New Teams Package not found. Please install new Teams from https://aka.ms/GetTeams ."
exit 1
}
Write-Host "Found new Teams Version: $NewTeamsPackageVersion"

$TMAPath = "{0}\WINDOWSAPPS\MSTEAMS_{1}_X64__8WEKYB3D8BBWE\MICROSOFTTEAMSMEETINGADDININSTALLER.MSI" -f $env:programfiles,$NewTeamsPackageVersion
if (-not ($TMAVersion = (Get-AppLockerFileInformation -Path $TMAPath | Select-Object -ExpandProperty Publisher).BinaryVersion))
{
Write-Host "Teams Meeting Addin not found in $TMAPath."
exit 1
}
Write-Host "Found Teams Meeting Addin Version: $TMAVersion"

$TMAParam= '/s /n /i:user "C:\Program Files (x86)\Microsoft\TeamsMeetingAddin{0}\x86\Microsoft.Teams.AddinLoader.dll"' -f $TMAVersion
Start-Process "C:\windows\System32\regsvr32.exe" -ArgumentList $TMAParam

With the newer versions of Outlook 365, when creating a new invitation, a Teams Call link is automatically added to every meeting, which might not be wanted by some customers. Here is a quick way to disable it for the whole tenant:

Connect-ExchangeOnline

Set-OrganizationConfig -OnlineMeetingsByDefaultEnabled $false

To check out if the settings has changed:

Get-OrganizationConfig | select OnlineMeetingsByDefaultEnabled