How to fix a faulty folder icon
QOS X changed the appearance of one of my folders. Although other folders still display with the regular, blue icon, my Music folder now looks like a file. How can I fix this?
ASelect the folder in the Finder and choose File > Get Info. At the top of the window that opens will be the current, incorrect icon. Click on that to select it, and then choose Edit > Cut to remove it. You can also use this capability to apply a custom icon to a file or folder by pasting a graphic into that image well.
Changing icons might indicate underlying disk problems. It’s worth starting up your Mac in Recovery mode (hold ç+R before you hear the startup sound) and running Disk Utility’s First Aid tool from there to check and repair your startup disk. Once done, restart your Mac as normal.
Incorrect, changing icons might indicate there’s an underlying problem to fix on your Mac’s disk
You can also reverse this process to use your own custom icon: copy an image and paste it over the icon at the top.
To revert a file or folder’s icon back to its default, select it at the top of Finder’s Get Info dialog, then pick Edit > Cut.