Qonderr :
clutchc :
I don't think that is your problem. That board has only had one BIOS up till now, and it supports every Ryzen chip available today. https://www.msi.com/Motherboard/support/B350-TOMAHAWK.html#support-cpu
I asked about this problem MSI Support and they say that it is my problem.
Okay. If their website is wrong, they need to correct it.
Here is the list of BIOS updates for that board:
https://www.msi.com/Motherboard/support/B350-TOMAHAWK.html#support_download
Grab the latest one and update your board. You don't need a special program to do that. It can be done either in the BIOS setup (MFlash) or from inside the Win environment (Live Update6 program on your disk). Scroll down to the bottom of the above page I just linked to and you will find another link. A "how to" link for updating the BIOS.