Hi.
I set my overall cache size to 50GB, then realized I don’t need that much allocated. But when I try to reduce it or zero it out, it reverts back to 50GB as soon as my mouse moves away from the text box. I have also deleted my cached regions.
Does anyone have any tips on how to zero it out?
Hello. You must delete the cache and then create it again.
Simply delete if you want it to 0.
Don’t forget to click “Apply and Save” 
The only things that are not greyed out are Cache New Region and Modify Cache. I did delete my cached region, but I’m not able to delete or change the 50GB in the Maximum Overall Cache Size box. Every time I change it, it changes back to 50GB before I can do anything else. Is there a file somewhere that I need to delete?
From my experience, there is no way to shrink that file.
Here is what I did to get rid of it,
First write down the directory you have already selected.
Create a new file to a directory other than the one your current file resides.
Open Windows Explorer (or some other way to change directories. e.g run etc) and navigate to the directory of your initial (large) file (the one you wrote down).
Inside you should see a MANUALCACHE.CCC file. It’s size should match the size you have originally selected in manual cache settings.
Delete that file.
You should see your storage size get back to what it was before you created that file.