My camera RAW program will no longer open multiple images with the "filmstrip" view on the left any longer. I've never had this happen before, but as of a couple of days ago it's almost never working like it was. I have updating everything on my laptop (macbook pro) and creative cloud. I can no longer batch edit, as each RAW photo it getting it's own window. My workflow is (and has always been) opening photoshop and selecting File->Open->selecting all my RAW images. I do not use Adobe Bridge.
I can either cmd-click on raws in the Finder or in the File > Open dialog *itself an abbreviated version of the Finder) and I get the Filmstrip.
So perhaps Adobe Camera Raw 9.9 needs a reset. Benjamin Root shows you exactly how: How To: Reset Camera Raw Preferences - YouTube