@fredldotme said:

So since you have the recovery already on your phone, try a flash without the bootstrap option again.

I already did that, tried it again now (also using a newer usb cable, as well as different usb port on the back of my pc).

The phone should reboot to recovery again and the UBports installer should start pushing the files onto the device.

It never starts doing that as long as I try to install the stable release again, which it has already downloaded previously. That only gets the installer stuck at "Rebooting".

Now I downloaded your dev release, and the phone seemed to try booting a couple times, unsuccessfully, while the installer was downloading UT, and got stuck on the Sony logo again. Ubports installer displayed the "Connection lost" alert.
adb shell commands are not giving any output, sadly:

[ben@catull-mnj ~]$ adb shell ls -lah /cache
adb: no devices/emulators found

I'm wondering if there's something wrong with the phone's usb port maybe...
Is it a possibility to save a UT image to an sdcard, and have recovery install it from there?

@kugiigi said:

Was it done pushing the installation files to the device?

Was what done?
I've tried rebooting it manually of course. Regular switching on goes to a boot loop like 3 or 4 times, then it ends up stuck at the Sony logo.
But I can get into recovery.
What are all the options under "Ubuntu options"?

• Replace Ubuntu android
• Install Ubuntu zip
• Install ubuntu preinstalled?

@kugiigi Is there any way to tell what exactly might be happening while Ubports installer is stuck on "Rebooting"? Any logs one might look into?
Also, 4 things have been mentioned to wipe from Recovery, but not everybdoy is mentioning the same ones:
data, system, Dalvik, cache
Last I tried wiping, I did all 4.
Was that correct?

@fredldotme Okay, the installer is stuck on "Rebooting" now, doing that since 5 mins. Should any button be pressed when connecting the device to the pc for the installer?

I can, however, get to Ubports recovery (not bootlooping, it's responsive this time) . Anything useful I could try from here?
Btw the battery turned out to be full actually.

@fredldotme Okay, I managed to flash TWRP and wiped system partition, Dalvik, Cache and Data. Turns out the battery was actually full. After that I flashed OEM binaries. Then I used UBports installer 0.5.5-beta, and it reported successful install in the end.
I saw the Ubports robot on the device "installing updates". Then it rebooted - stuck on the Sony logo again.
I can, however, get to Ubports recovery. Anything useful I could do there?

UPDATE: I can now get to Ubports Recovery screen. From there it's a boot loop, so back to the state right after my first flashing attempt. Maybe it did charge even while not booting successfully. Will try to reflash TWRP.
Question: in which mode should I connect to PC to flash TWRP? It's kinda not mentioned anywhere.

It does not display the large red battery icon when I plug in the charger.
I've found now that when it's off and I connect it to the Pc, the green LED comes on.
(also green when pressing vol down at connect, blue when pressing vol up)

1. Is the battery charging when connected to the Pc like this (switched off)?
2. Would you say it's reasonably safe to try and install TWRP in this state (with battery maybe depleted)?
3. If 1. is a no, will the battery charge while TWRP is running?

Oh and also, adb devices is listing no devices

@kugiigi I'm worried the battery may be too empty, and that charging is failing because it can't boot. Can anyone confirm the battery isn't being charged unless the device manages to boot?

I have 1 failed attempt at installing Ubports on F5121, using the Ubports installer from a Linux desktop. I have already flashed OEM binaries and run the installer, the device already got to the boot screen (the one visible at 12:56 in this video: https://youtu.be/lA7l9rcuDiQ?t=776) after that. Now it's stuck at the SONY black-on-white splash screen when I try to charge it. I can press power+volume up until three vibrations, which makes it reboot and go to Sony splash screen again. The LED remains red (indicating it's charging, I guess) during the boot message " your device has been unlocked and can't be trusted. Your device will boot in 5 seconds." When the Sony splashscreen comes up, the LED goes out.
Is it supposed to try booting as soon as I plug in the charger?