LineageOS Update Failed: Unable to mount /data I recently installed MicroG for LineageOS on my OnePlus 5. After downloading the latest update using the updater in settings, I clicked install. The phone rebooted into TWRP and started to update itself but showed multiple error messages in red which said failed to mount /data. The phone booted back into Lineage and said that the update failed to install. In the updater, the same update I had tried to install still had an install button next to it, also indicating that the update had failed. I tried installing the update again and got the same result.

Why is the update not installing, and what can I do to get it to install?

*Update: I've tried installing the newer April 1st, 8th, and 15th updates, to no avail. I also tried updating TWRP and installing the update again, but it failed to install again, with the same error messages in TWRP. I am no longer getting notifications that the update failed to install, but it is still showing in settings as ready to install, meaning it isn't installed yet. I read online to try an older TWRP version, which didn't work either.
Solved: Use TWRP Version 3.3.0-0.