What rom are you now?
install twrp1217 flash rom 8.12.27 (https://drive.google.com/file/d/1U_D0-N0Tf0cRMuuD0eCEWsXi28L_29H8/view)
after that install twrp 1227 (https://drive.google.com/file/d/1CKDNVE9Wm68T1UwToVY6Q6XC2bzFn3o-/view) it should work
and then install rom 9.1.3
it should be ok
.....
I always clean and format data before installing new rom.
Thanks for your reply my friend. One question from my side: Will this procedure work for a dirty installation or MUST I format data? My priority is not to lose anything on my phone (neither apps nor files).