I tried switching from Fairphone OS to LineageOS today. I was on the latest Fairphone OS version before (18.04.1, fairly certain about that) and encryption is enabled on my device.
I followed the instructions in the LineageOS installation guide and during the installation process, everything went well. I used the following software versions:
- TWRP 3.2.1
- Open GApps ARM 7.1 Mini
Like I said, the installation seemed to have gone fine, after rebooting the system I see the new LineageOS bootscreen and then I get asked for my unlock pattern.
However, when entering it the first time it just says “Wrong pattern” and after entering it a second time I get a screen saying something along the lines of "Decryption unsuccessful - The password you entered is correct, but unfortunately your data is corrupt."
It tells me to reset my phone to fix it, I pressed the reset-button, it took me back to TWRP and the script ran without errors. However, on the next reboot I get the exact same behaviour.
Fortunately I could restore the backup I created beforehand and now I’m back to Fairphone OS, but I’d still like to switch if possible. Does anyone have any ideas what this is about and how to fix it?