Users of the Microsoft IME for Japanese or Chinese languages might experience issues when attempting various tasks. Input may have issues, you may receive unexpected results or you may be unable to enter text.

The Affected platforms are:

Client: Windows 10, version 20H2, Windows 10, version 2004
Server: Windows Server, version 20H2, Windows Server, version 2004

Microsoft is Investigating:

  • The ImmGetCompositionString() function unexpectedly returns full-width Hiragana when using the current Microsoft IME for Japanese. Half-width Katakana is the expected character set, as that is what is returned with previous versions of the Microsoft Japanese IME.
  • In certain circumstances such as a form with limited input options or handling WM_CHAR message to the input control, apps might be unable to receive keyboard input from users of Microsoft IME for Japanese or Chinese.
  • Microsoft IME for Japanese might not react as expected when using SetInputScope() API to change or set the conversion mode for apps.
  • When you select a text box and the ImeMode property is set to disabled, the ImeMode indicator on the right side of the Windows taskbar might display the incorrect mode when using Microsoft IME for Japanese.

Workaround:

  • You can mitigate these Issues in the short term by following the steps below to enable compatibility mode:
  • Select Start, type Settings, and select it or press enter.
  • Type IME settings into the search box within Settings and select the IME settings that are appropriate to your language, for example Japanese IME Settings.
  • Select General.
  • Turn on Use previous version of Microsoft IME.

Note: We do not recommend using the compatibility setting for the long term, but rather as a temporary workaround for users who are impacted by this issue.

Microsoft is working on a resolution and will provide an update in an upcoming release.

Source: Support.Microsoft.com