First I'd like to state I am fairly ignorant of Adobe Camera Raw, as I've been using Lightroom for years. I'm only replying because you seem under a close time constraint.
Are you working within PS CC? It seems that Camera Raw no longer exists independently, but rather as a plug in within PS CC. I mention this because I seem to recall at one point it could function as an independent app. I am just wondering if you were using an old version of ACR, that may have been overwritten, or started within PS CC.
That is the only help I can offer as far as ACR, and may have nothing to do with your issue.
If you must get these done very soon and can't solve ACR, I'd also suggest giving Lightroom a shot, if you've access to it, just this one time, until you get ACR running again. Open it up, Create an intial library, like 2015 or Lightroom. Import the images you'd like to copy/convert, in a way that that the originals aren't moved and copies of the RAWs, (or DNGs) are made. Then select all, in the most recent import folder, and turn around and export them in whatever form you desire. Also, Lightroom is non-destructive, so, if you'd like to try making adjustments before exporting, under the develop tab, any alterations or adjustments you might make before exporting are completely reversible.
I realize changing one's workflow, and learning a new app, may be too much effort at this point, and very possibly require too much time, but you might pick it up quickly enough to get 'er done on time.
That is all the help I can offer. Wish I knew more about ACR.
When you say “Copy RAW Images to Tiff or Jpeg” are you using the Save Image function from within the plug-in or some other operation, perhaps with Bridge or Photoshop, itself?
Without a lot of information, it sounds to me like a permissions problem for whatever folder you have designated the Save Image is destined for.