Describes the cause and action for error messages.
Error Message(English)：
is not the default program
How to See Which Files Excel 2013 Will Open By Default - Solve Your ...
https://www.solveyourtech.com/see-files-excel-2013-will-open-default/
Libreoffice is again and again setting itself as default program ...
https://ask.libreoffice.org/en/question/20589/libreoffice-is-again-and-again-setting-itself-as-defau・・・
Word Options - Online Resource - BetterSolutions.com
https://bettersolutions.com/word/options/options.htm
Options.AlertIfNotDefault property (Word) | Microsoft Docs
https://docs.microsoft.com/en-us/office/vba/api/word.options.alertifnotdefault
Microsoft.Office.Interop.Word - Microsoft Docs
https://docs.microsoft.com/ja-jp/dotnet/api/microsoft.office.interop.word.options
Finding the default application for opening a particular file type ...
https://stackoverflow.com/questions/162331/finding-the-default-application-for-opening-a-particular-・・・
ubuntu - LyX: change PDF viewer - TeX - LaTeX Stack Exchange
https://tex.stackexchange.com/questions/73233/lyx-change-pdf-viewer?noredirect=1&lq=1
Convert CSV to Excel: open or import CSV files into Excel worksheets
https://www.ablebits.com/office-addins-blog/2014/05/01/convert-csv-excel/
.xlsx and .docx files are opened as zip file - Applications ...
https://forum.manjaro.org/t/xlsx-and-docx-files-are-opened-as-zip-file/25814