Low disk space available in Audition

I am late to the party but I use Windows 10 and I am experiencing the same issue on Audition.

I save these files directly to a Micro SD with over 50 GB left, and the limit says I only have 15 GB.  

This may reflect my C:/ Drive, which has very little space left on it, but I have taken every precaution to save all my Audition files to my partitioned D:/ Drive, the Micro SD card.  

What gives?

I have no idea, but it's definitely a Mac thing; it's reported correctly on both Windows machines here. There used to be a setting that would let you constrain the amount of space that Audition would automatically leave on a disk, but people got confused about what it meant, so it was dropped. But that would let you set the effective size that the media cache files could reach, and that was well less than the capacity of the drive.

Personally I wouldn't worry about it too much. If you right-click in that area, there's an option to turn that bit of display off. When you get the disk up to what Audition thinks is the size limit, it will tell you why! Meanwhile, perhaps another Mac user can tell us if the same thing happens?