( Translated into English using Google Translator )
This issue is known to be triggered by a security update related update released on April 15.
This issue can be avoided by reverting to the March version.
Microsoft is already aware that this is a security update issue.
There is also an announcement that a fix update is being prepared.
It affects Office365 (Excel) / Excel2019 / Excel2016 / Excel2013 / Excel2010.
Excel 2007 and earlier versions are no longer supported. Therefore, there is
no security update, so it is not affected.
This is a bug related to DBCS characters (Japanese, Korean, Chinese etc.).
Therefore, it is not a problem in the US and Europe.
( May 7 18:00 )
Issue information has been added to the Microsoft troubleshooting list.
Office365(Excel) Fixes or workarounds for recent issues
https://support.office.com/en-us/article/2596-49d932ce-0240-49cf-94df-1587d9d97093
The issue information is below.
Excel/Word/PowerPoint file becomes corrupt when opening a file that
contains a VBA project or after enabling a macro in an open file
https://support.office.com/en-us/article/ad6ee6ca-db23-4614-a403-282821eb99f6
--- Conditions for issue ---
Post thread by Msdn Forum / Office Support Team (Japanese)
https://social.msdn.microsoft.com/Forums/ja-JP/6c3fa724-25c9-408e-bdde-245c9ea1ad8a
(Case A)
The name of the library (DLL) referenced from VBAProject contains DBCS characters.
(Case B)
The name of the Excel file referenced from VBAProject or the storage path of the
file contains DBCS characters.
(In this case, the only referencing file format is Excel 97-2003 format (.xls or .xla).)
(Case C)
As of May 1st, it is not listed in the thread above,
An error occurs in the workbook created with "User account name containing DBCS characters".
The undetermined condition is posted (thread below, Japanese).
https://answers.microsoft.com/thread/121fef4a-e11e-4dfe-86e9-f89dcaa2f245
(In this case, both Excel 97-2003 format / Excel 2007 format are affected)
--- How to revert to the March version ---
(1) Office365 (Excel) / Excel2019 / Excel2016
(a) C2R version (Click to Run)
You can recover by rolling back to "16.0.12624.20382" delivered on March 31.
(b) For MSI version (installer)
You can recover by uninstalling "KB4484273".
(2) Excel2013
(a) C2R version (Click to Run)
You can recover by rolling back to "15.0.5223.1001" delivered on March 13.
(b) For MSI version (installer)
You can recover by uninstalling "KB4484283".
(3) Excel2010
You can recover by uninstalling "KB4484285".
(Note)
Store app version Office cannot be handled by this method.
First, you need to switch to the desktop version (C2R version).
After reinstalling the desktop version, roll back to the March version.
(4) How to roll back to March version with C2R version
(a) Execute "Command Prompt" as an administrator.
[Start button > Right-click Command Prompt > Other > Run as administrator]
(b) Type the following two commands
(i) Office365(Excel)/Excel2019/Excel2016
cd %programfiles%\Common Files\Microsoft Shared\ClickToRun
officec2rclient.exe /update user updatetoversion=16.0.12624.20382
(ii) Excel2013
cd %programfiles%\Microsoft Office 15\ClientX64
officec2rclient.exe /update user updatetoversion=15.0.5223.1001
(Note)
[ For 32bit-Windows, ClientX64 -> ClientX86 ]
(c) After typing 2 commands, the following 3 popups will be displayed in
sequence for a while.
[ Downloading Office updates ]
[ Applying update program ]
[ Update program installed ]
(d) In order not to update again, after rollback is completed,
set "Disable update" in [ Account > Update option ].
(5) How to uninstall KB in Excel2019 / Excel2016(MSI version) and Excel2010
(a) Select the corresponding KB from the list of
[ Control Panel > Programs > Show Updates ]
and click the "Uninstall" button
Excel2019/Excel2016 : KB4484273
Excel2013 : KB4484283
Excel2010 : KB4484285
(b) Use one of the following methods so that it will not be updated again.
(i) [ Windows Settings > Update & Security > Pause update for 7 days ]
(ii) Hide the target KB by "Show or hide updates Troubleshooter"
https://support.microsoft.com/en-us/help/3183922
## Since this is not a question, you do not need to reply to this thread. ##