ting him wrote:
After upgrade to Mac OS 14, all my folder and file icons at the external hdd was gone
I can't even edit the existing one or create a new folder to edit the icon.
Is that a bug after upgrade? Anyone know how to fix it?
It's quit annoying to redo the procedure.
Change icons for files or folders on Mac - Apple Support (SG)
https://discussions.apple.com/content/attachment/2dafaba7-65ba-4490-9c84-717eebb6b484
Use list view and don't torment yourself

You can submit a bug report or your Apple Feedback here: Product Feedback - Apple
I would wait for some point update to follow macOS 14 and see if it changes...
Keep your Mac up to date - Apple Support
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Contact Apple for support and service - Apple Support