I have an RB433 and a 493 that both perform uselessly after upgrade to 5.4 - 100% CPU and essentially no operation - with winbox all devices appear to be absent - wireless will accept a connection on the 433 but then drops it. Basic ip routing appears to be working but very poor and laggardly.
On the 493, works fine until it receives an OVPN connect request when the 100% cpu starts - so after about 20s after re-boot it is useless.
How do I back out back to 4.16?
upload 4.16 npk, system package downgrade , then reboot it.