Installation of RROS-Q-8.5.* results in 'failed to mount /vendor (no such device)'

[_sad]

Got an update notification on my nexus 6p with installed RR-P-v7.0.2 on it. After installing this OTA update i got an infinite booting screen. I loaded back into twrp and got a password prompt to mount partitions (i didn't have any passwords anywhere on my phone before). I could neither access internal storage from within recovery, nor from pc. Installed newest version of TWRP (3.4.0), didn't help. Did a full wipe, which finally helped and allowed me to see and transfer files to my internal storage. Downloaded RROS-Q-8.5.9 zip from official site, tried to install again, which resulted in same error as before. Then i found out that i can load the system even with this error presenting, but i CAN'T install magisc. I don't know if it is me, who does something wrong or is it error in system zip? Also before each attempt to reinstall RROS-Q-8.5.9 i see logs, that magisc binaries r missing, i don't know if that might be the reason of vendor error in the end. The only way i can fix it is flash official vendor.img and flash older system image. But i really want to have RROS-Q-8.5.9 on my phone, with magics. Initially i posted it in 'Nexus 6P Q&A, Help & Troubleshooting', but no1 responded, so i duplicated this post here in case some1 knows the answer. Please help.

 

[voidz777]

I'm sorry for being unfriendly. I'm lazy.
Most android10rom for angler cannot be flashed without using this twrp. If you want to switch back to pie rom, use the official twrp.
Then your latest post is on the nexus6 shamu thread.
Everyone makes a mistake because the terminal names are very similar. So don't complain to kae.
https://androidfilehost.com/?fid=4349826312261691698

For the time being, there are few posts on this device, so I think it's okay to write here.
https://forum.xda-developers.com/nexus-6p/development/9-0-resurrection-remix-v7-0-t3892786

 

[_sad]

Thank you for your response anyway. Tho i managed to flash the rom without getting this vendor error at the end. Steps i did: flashed back to RR7.1.2, did a backup, wiped everything including system, than flashed new RR8.6.0, which flashed fine with no errors. After this i flashed magisk right away, and it went fine (it couldn't before, cuz of the error 'failed to mount /vendor' after attempting to flash OS zip), with exception of an error 'failed to mount /vendor (no such device)'. Still i've got nexus 6p with android 10 and root, which can't update, cuz of the permanent vendor error after i flashed magisk.
Next time i will need to flash anything, i will use TWRP u suggested. Thank you again.