@fips After about 3 hours in splash screen I finally forced shutdown. I don´t think it would have booted later on.....
I would get a dora (instead of dora_dsds) if i where sure that thats the problem.
Maybe it was naive of me to just flach the ub touch to a Xperia dualsim (Code dora_dsds).....
So does anybody know if it is a problem installing ubuntu touch (for dora) on a dora_dsds ?
@Keneda Thanks for the tips, but my device is now stalled in splash screen fpr over 1 hour .... im still waiting and hoping 
Seriuos: does anybody happen to know if the dora Ubuntu will work on a dora_dsds (dualsim xperia x performance) ?
It was really good advice, i made up to the installer saying "Sucess!" but the phone still stalls in the white screen with 'SONY' - logo !
maybe it is because i have a DUAL-SIM device dora-dsds (NOT dora ???? )
Its a little bit frustrating ....... but i really want ubuntu touch !
Best regarts,
Fips
@Lakotaubp Thanks, I will check it out soon !
(Busy.... )
Stuck in Loop White Screen with 'SONY'-Logo , warning screen 'Your device was unlocked and cant betrusted'
I tried to install Ubuntu Touch on my Sony Xperia x Performance dora_dsds. It hab stock android 8.
I activated developer options and usb debugging, unlocked the oem bootloader.
UBports Installer started but stalled with preparing image.
The device entered a loop with White Screen with 'SONY'-Logo and warning screen 'Your device was unlocked and cant betrusted' and the UBports installer lost the connection to the device.
I tried multiple times in fastboot mode to install (with the installer), but h the behavior was always as above.
What am I doing wrong ?
Is there an alternative way to flash? I found:
https://forum.xda-developers.com/xperia-x-performance/development/testing-ubuntu-touch-xperia-x-t3960133
but I really didnt find where to get rootfs.img and so on ....
I would really apriciate any help !
Fips