Hello, You did not say you flashed the sailfish image too. You only said flashed cm12.1 then you got the boot loop. The proper installation is in twrp 2.8.7:do a factory reset, flash cm12.1 flash sailfish image reboot This will (should) work with either with both twrps the 'twrp_multirom_hammerhead_2150630.img' (twrp 2.8.7.0) or the newer 'twrp_multirom_hammerhead_20160210.img' (twrp v3.3). (However with this latter you cannot flash any zip files over a secondary rom, if you need to do that just flash the newer twrp and reboot into recovery. I had been swapped between these two twrps when was playing with UT and different versions of Sailfish where I tried the SFDroid and other stuff. If you only need Sailfish, you don't need this magic that I wrote in this brackets. )