Ryzen 7 3700x with kernel 5.12.11-1.el7.elrepo.x86_64 Panic

[mrmarkuz (Markus Neuberger)]

Maybe try another kernel or reinstall it to fix possible initramfs issues:

Kernel Panic - after update

I suggest you to remove kernel and reinstall it with Software Center. To remove it: start NethServer with an old kernel remove kernel (e.g. yum remove kernel-3.10.0-229.el7.x86_64) download software updates