Can't rename a folder in Finder...

I'm trying to rename a folder on my Mac in Finder and I can't do it. Clicking on the name doesn't bring up the editing window, and, when I go to "Get Info," the name of the folder is grayed-out and I can't change it there, either.

I did put a shortcut for this folder in my Finder sidebar. The folder is on an external Thunderbolt RAID drive (if that matters). I just checked, and there is another folder I put a shortcut for there and I can't change it's name, either (but I can change the name of every other folder I try to change).

So this must have something to do with having created the sidebar shortcut. However, I deleted that shortcut and still can't change the folder's name. It is a shared folder, too, but even when I turn sharing off for it, I can't rename it.

What's happening here? Why can't I rename this folder? And is there a way I can rename it?

Thanks!

running Yosemite 10.10.4