You can try changing the setting at Control Panel > Default Programs > Set Associations
This might help with that:
https://support.microsoft.com/en-us/help/18539/windows-7-change-default-programs
But if the CC and Mods work I wouldn't worry too much about the icon.
mine do not work, they are all on notepad but it used to be a blank white icon and worked.
Shouldn't really matter what program is associated with package files for them to work
Do you have custom content turned on in your game options ?
Mine went like that before. I still put it in my mods folder.
