@turtlenate

Wasted a lot of time over this issue with F5121 which was previously running Sailfish OS. In my case had saved TAbackup prior to bootloader unlock for Sailfish so downgraded device back to MM with Androxyde Flashtool, restored DRM (Androxyde Advanced settings), upgraded to stock Oreo, bootloader unlocked on latest firmware, turn on USB debugging, installed twrp-3.2.2-0-suzu.img, wipe then advanced wipe for cache, dalvik cache, data and system, fastboot flash oem SW_binaries_for_Xperia_AOSP_N_MR1_5.7_r1_v08_loire.img and then run UBports installer 0.14.4-Beta to install 16.04/community/fredldotme/devel and got "spinning white circle" this time. Remember to remove any microSD card for any subsequent OTA updates, now on v 10* OS build number 2020-01-01/2.

@marklynch
Stock Xperia images downloaded using Xperifirm within Androxyde Flashtool. If you want to find older MM versions you have to look under "Commercial & Journalists". Another source could be:link text

@livrecinq

Wasted a lot of time over this issue with my F5121 which was previously running Sailfish OS using Ubuntu 18.04 LTS and Mac OSX . In my case had previously saved TAbackup prior to bootloader unlock for Sailfish, so downgraded device back to MM with Androxyde Flashtool, restored DRM (Androxyde Advanced settings), upgraded to stock Oreo, bootloader unlocked on latest firmware, turn on USB debugging, installed twrp-3.2.2-0-suzu.img, reboot into "recovery mode" TWRP wipe then advanced wipe for cache, dalvik cache, data and system, fastboot flash oem SW_binaries_for_Xperia_AOSP_N_MR1_5.7_r1_v08_loire.img and then ran UBports installer 0.14.4-Beta upon Mac OSX to install 16.04/community/fredldotme/devel and got "spinning white circle" this time. Remember to remove any microSD card for any subsequent OTA updates, now on v 10* OS build number 2020-01-01/2.

@turtlenate

Wasted a lot of time over this issue with F5121 which was previously running Sailfish OS. In my case had saved TAbackup prior to bootloader unlock for Sailfish so downgraded device back to MM with Androxyde Flashtool, restored DRM (Androxyde Advanced settings), upgraded to stock Oreo, bootloader unlocked on latest firmware, turn on USB debugging, installed twrp-3.2.2-0-suzu.img, wipe then advanced wipe for cache, dalvik cache, data and system, fastboot flash oem SW_binaries_for_Xperia_AOSP_N_MR1_5.7_r1_v08_loire.img and then run UBports installer 0.14.4-Beta to install 16.04/community/fredldotme/devel and got "spinning white circle" this time. Remember to remove any microSD card for any subsequent OTA updates, now on v 10* OS build number 2020-01-01/2.