flashing files with adoptable storage

Hi, I'm using Dirty Unicorns on my Redmi2. Since it's marshmallow, I'm using adoptable storage, i.e. using my sd card as internal storage, so I can install apps to the sd card. but since this mode formats and encrypts the sd card, I can't access files that I want to flash with TWRP when booting recovery. I thought TWRP 3 was supposed to support adoptable storage, but even after updating it I can't seem to get it working. Am I forgetting something here?

Thanks in advance.