Does TWRP recovery support encrypted /data/ partition?
I've managed to solve this issue. Apparently the ported TWRP image didn't have support for encryption. That's why it tried to mount the encrypted /data/ partition. I've build the image from source, and I've set the following flag:

TW_INCLUDE_CRYPTO := true


Now it can detect the encrypted partition:



The only problem is that it can't decrypt the data with the right password. Maybe something else is missing.