I was silly and used the GUI for trying to update… instead of ssu release XXX and version --dup. Somewhere close to the end of the progress bar, the infamous message “update failed” appeared and the Xperia 10 plus rebooted. I’m able to pass the security code but when the phone is trying to load into the GUI, the screen just flashes 3 times with a message saying that “no apps are installed”.
I though that it’s an easy fix via Recovery mode, volume key up (blue light) + USB cable and in Terminal: sudo fastboot boot hybris-recovery.img (I went to Jolla store to download the one for the phone) but I cannot get into it. I do not know what I’m doing wrong here… . I tried serval Linux laptops, even virtual Windows and several USB cables but. Beyond "Sending ‘boot.img’ (21988 KB) … " I can’t go any further to enter the Recovery mode. I’m honestly clueless now and if anyone of you has an idea what else I could try, I would be happy.
Follow official guide on recovery mode, you need to flash two files first nvm it’s on XIII, no idea about 10 plus, then try Bricked Phone while updating - #2 by throwaway69 if you had developer mode enabled, otherwise it’s probably reflash
You have to use an usb2-hub, because native usb3-ports have some troubles on most pcs… You can use sf-recovery and may be lineageos-recovery or twrp to mount partitions and copy data via ssh and usb or lan.
Thankfully I found an older desktop were I was able to get into the Recovery mode. I totally forgot about the usb3 causing trouble here.
Yeah 4.6 update is a pretty rough ride, my initial comment mentioned XIII specific recovery mode details as didn’t notice it was about 10+, follow jolla guides to the closest model in order to get into recovery, once you get shell option your data should be safe (though importing a rough cp of your home will likely be a bumpy ride), but it should be possible to finish the update with clues from @nthn, good luck