Describes the cause and action for error messages.
Error Message(English)：
protect workbook cancel
Add or remove protection in your document, workbook, or presentation ...
https://support.office.com/en-us/article/add-or-remove-protection-in-your-document-workbook-or-prese・・・
ブック保護・解除（Protect メソッド・Unprotect メソッド ... - Excel（エクセル）
https://excelwork.info/excel/protectbook/
Worksheet.Protect メソッド (Excel) - Microsoft Docs
https://docs.microsoft.com/ja-jp/office/vba/api/excel.worksheet.protect
構文
https://docs.microsoft.com/ja-jp/office/vba/api/excel.worksheet.protect#syntax
パラメーター
https://docs.microsoft.com/ja-jp/office/vba/api/excel.worksheet.protect#parameters
解説
https://docs.microsoft.com/ja-jp/office/vba/api/excel.worksheet.protect#remarks
How to protect worksheets and unprotect Excel sheet without password
https://www.ablebits.com/office-addins-blog/2016/02/10/protect-unprotect-excel-sheet-password/
Excel worksheet protection ...
https://www.ablebits.com/office-addins-blog/2016/02/10/protect-unprotect-excel-sheet-password/#excel・・・
How to unlock Excel ...
https://www.ablebits.com/office-addins-blog/2016/02/10/protect-unprotect-excel-sheet-password/#unloc・・・