Originally Posted by misticalx
Do you have Xposed installed? If so, that's why. The latest version 2.6 that just came out the other day has not fixed it yet either. You can either use an alternative application such as Vaulty or not use Xposed until it's hopefully fixed.
I can confirm that uninstalling Xposed framework fixed this error on my rooted Sprint S5 with GPU900PVPU1AND2.
Thank you, I was worried I had lost all my porn! (what else would you use Private Mode for?)
In my experience, it appears to copy everything to the Internal SD when you "Move to Private". The Free space on the Internal storage for "Miscellaneous Files" seems to confirm this.
Is there a way to store Private Files on the SD card?