Sam,
Try to open the style In EndNote and edit it. Does it allow you to edit it? If it doesn’t please try to copy another version of the style and then do a SAVE AS so that it saves a new version of the style–you don’t have to do anything but add a few spaces in the Style Descritpion area.
If you are still having issues with the file please post it here so I can take a look.
Thanks,
Cheryl - The EndNote Team