m box firmware problems

I have an old m box running helix 14.1 with firmware 4.2.2
I kept getting notification to update to 17.1 or else problems will start.
My unit worked just fine but I uninstalled 14.1 and tried to download 17.1
as per several You tube videos. Then I find out out I need firmware 5.0 or higher
to run. I am not a software person but followed the instructions and no mention of this.
How do I get proper firmware for my box? Since I think all boxes have their unique
bit language which needs updating.

Thank you for any help

Michael