After you have added the Japanese language option to a Windows 10 PC you might find that when you right click on the IME menu in the system tray you cannot select anything other than Half-width Alphanumeric.
This usually indicates that files are missing from the Japanese language pack dictionary.
To fix the issue run the fix from Software Centre.
Please suggest an improvement
(login needed, link opens in new window)
Your views are welcome and will help other readers of this page.
This is question number 2903, which appears in the following categories: