I can not upgrade from 5.26 to 6.x x86

Hello!
I have a problem
RouterOS 5.26 on x86. I want to upgrade to 6.6
After update i get kernel panic

i updated to 6.0 b1 and b2 it’s ok
i updated to 6.0 b3, 6.0 rc1, 6.1 - kernel panic

reset configuration… and no effect, kernel panic on b3 and newer

on /system licence: upgradable to v6.x

how to update by latest version?

Thanx!

Try to install with netinstall or CD install.

Nothing helps.
Wanted to clarify that I was doing it for Citrix XenServer 5.6