I have upgraded all my RS2 to 2.22 via ReachView without a problem.
However, when I upgraded one of my RS+ and rebooted it (again, via ReachView), the system won’t load anymore. It got stuck, with the power led (amber) always on. The other leds (blue and green) remained off. I tried to manually reboot it many times after that, but the behaviour is the same.
The RS+ was running 2.18.1 before the upgrade.