Hi there…
With the new prices i could not resist buying a licence for my xperia.
Everything works nice and i made the last sauna update but the fingerprint reader annoys me.
When i´m holding the phone wrong and touch the fingerprint reader for a couple of seconds the phone says bye bye and shut down.
How can i disable this behaviour ?
It could at least ask if i want to shut down 
Shut Down should only happen with a physical press of the power button. Pressing for around 2 seconds should bring up the options to Shut Down of Reboot (top of screen), a prolonged press around 4 seconds will start the shut down process, but just touching the power button (not pressing) should not cause a shutdown. Perhaps the Xperia 10 differs from my Xperia 10II.
I’m not sure about disabling the behaviour, as I believe this is changed using MCETOOLS via terminal, as far as I am aware, there are no user options to change this behaviour. Getting settings wrong with MCETOOLS could cause undesirable effects.
Thanks for your reply. That is strange. To sad the whole thing is glued. I can´t even check if something is wrong inside.
@tomauswustrow asked for touching the fingerprint reader. As I understand his post, touching the FP sensor causes a crash/reboot on his phone.
oh it´s not a reboot. It just says “Auf wiedersehen” and shuts down. I have now deleted the saved fingerprint and just as i write this her it does it again. Maybe a hardwareproblem ?
I don’t think so. Maybe something went wrong at flashing time and reflashing solves the problem.
i will try a reflash and give feedback than 
I did a reflash and now it´s just shutting without even touching it. I just let it charge for now and check tomorrow again. Meanwhile i´m just waiting for my Jolla C replacement parts
Maybe it’s a dead battery problem and the phone shutted down from power failure/empty battery. Charge over night, tomorrow let the charger connected, boot the device and please let us know, I’m curious now!
edit: What did/does the battery level display say?
Got it full charged but the bug remains. But after thinking about it i´m pretty sure it was not like this with the 4.5 version. To sad there are no old versions around somewhere to try making a downgrade. I have found the old topic with the github/ torrent links but there are no seeders.
Downgrading the OS is a sure way to break the device.
Is the fingerprint reader not on the power button of the Xperia 10?
Nope. It´s above the fingerprintreader. I´m in contact with the Jolla service now. Have collected some logs and screenshots… i will update here.
tiny update before i spent the rest of the evening with my wife. I did a blank reflash with 4.5.0.24 i found on my external harddisk. The bug is not there anymore. Ok the fingerprint reader works not as it should but no random reboots the last 20 minutes or so. Could add my O365 account and everything looks good until now. I will see if the support guys can see something fishy in my logfiles.
Last update the phone works nice it seems.
The support guys could not see anything in my logs and i had to investigate further.
The battery was the bad part. Just coincidence with the fingerprint reader 
Got a new one from subtel in Germany and everything works.