Describes the cause and action for error messages.
Error Message(English)：
cannot select data validation excel
Excel Data Validation Tips and Troubleshooting - Contextures
https://www.contextures.com/xlDataVal08.html
Data Validation List With ...
https://www.contextures.com/xlDataVal08.html#symbols
Data Validation Dropdowns ...
https://www.contextures.com/xlDataVal08.html#Change
Missing Arrows
https://www.contextures.com/xlDataVal08.html#ArrowsNotVisible
Excel troubleshooting ? why does data validation work on my desktop ...
https://ion.icaew.com/itcounts/b/weblog/posts/excel-troubleshooting-why-does-data-validation-work-on・・・
More on data validation - Excel - Office Support - Office 365
https://support.office.com/en-ie/article/more-on-data-validation-f38dee73-9900-4ca6-9301-8a5f6e1f0c4・・・
troubleshooting - Unlocking Locked Drop Down boxes in Excel ...
https://superuser.com/questions/13945/unlocking-locked-drop-down-boxes-in-excel
Excel Dropdowns Done Right: Data Validation and Named Ranges ...
https://analyticsdemystified.com/excel-tips/excel-dropdowns-done-right-data-validation-and-named-ran・・・
Excel Data Validation Arrows Are Missing - YouTube
https://www.youtube.com/watch?v=BiEOTSlCFCs