TWRP 3.2.3 asks for a decrypt password at startup, which I never set. Ignoring with 'cancel' leads to the main menu, but then the internal storage is marked as 0 byte (e.g. when trying to backup), which is not the case.
I understand this is related to default encryption of the data partition (correct?) by Android (my phone has Android One).
Is there a default password?
The PIN/password used to login into the regular OS do NOT work. I've seen many answers saying so (e.g. here or here ), it is not true (at least for my version of Android). I tried with numerical PIN, password, or nothing (each time going back to factory reset), and nothing worked in TWRP.
I know there are other related questions, but none of the answer provides details or seem confident enough:
This answer refers to a misterious "disable force encryption" package, which I've also read about in other posts.
Is it really the way to go? What exactly is that package? And what does it do?
Can I not completely disable encryption in Android OS?
Extra:
I want to mention that I manged to circumvent the problem temporarily, by recreating the data filesystem within TWRP. This of course wipes out your data, but at least afterwards TWRP sees your internal storage and one can do a backup of the system. However, upon reboot the phone gets stuck in the initial loading (white screen with color bar in Android one), so I have to reboot again to the stock recovery and do a reset. Which brings back encryption, and I am back to square 1.