A known issue is affecting Microsoft 365 customers using Microsoft Outlook, causing the application to freeze or hang when copying text. The problem occurs on systems running Outlook Current Channel Version 2409 (Build 18025.20096) or higher, as well as when using languages with an Input Method Editor (IME).

Symptoms of the Issue

When selecting text in a classic Outlook email and pressing the Ctrl+C shortcut to copy it, the application may become unresponsive, freezing or hanging.

Technical Details

The issue is related to the interaction between the IME and Outlook’s rendering engine. When the IME is active, it can interfere with the way Outlook renders text, leading to the freeze.

Investigation and Mitigation Measures

Microsoft’s Outlook team is investigating this newly acknowledged issue and will provide more information about mitigation measures or a fix as soon as available. In the meantime, affected customers can use the following temporary workarounds to resolve the issue:

Temporary Workarounds

Revert to Previous IME Version

To bypass the issue, users can revert to a previous version of their Input Method Editor (IME). This involves updating the IME settings in the Windows Settings app.

• Open the Settings app and search for “IME settings.”
• Select the language’s IME settings and click on General.
• Enable the “Use previous version of Microsoft IME” option.

Revert Outlook to Previous Build

Another workaround is to revert Outlook to a previous build that is not affected by this known issue. To do this, follow these steps:

1. Open Command Prompt in Windows Search.
2. Right-click the “Command Prompt” icon and select Run as administrator.
3. In the Command Prompt window, paste the following commands and press Enter after each:

   bash
   cd %programfiles%\Common Files\Microsoft Shared\ClickToRun
   officec2rclient.exe /update user updatetoversion=16.0.17928.20156
   

Additional Information

This issue is not an isolated problem, as Microsoft previously fixed a bug in September that affected multiple apps, including Outlook, Word, Excel, and OneNote, when typing or spell-checking text.

In addition to these workarounds, users may also recall a previous temporary fix for another known issue that caused Gmail sign-in issues for classic Outlook users and resulted in Outlook crashing after opening.