[SOLVED] How do I fix modules when downgrading to an older kernel package?

Not sure why but a kernel actually broke a wine wrapper to run windows VSTs https://github.com/osxmidi/LinVst/issues/86 . So I downgraded my kernel and it's fixed but I have a few module issues I'm not sure how to fix.

 vboxdrv: version magic '5.2.0-arch2-1-ARCH SMP preempt mod_unload ' should be '5.1.15-arch1-1-ARCH SMP preempt mod_unload '
vboxdrv: version magic '5.2.0-arch2-1-ARCH SMP preempt mod_unload ' should be '5.1.15-arch1-1-ARCH SMP preempt mod_unload '
vboxdrv: version magic '5.2.0-arch2-1-ARCH SMP preempt mod_unload ' should be '5.1.15-arch1-1-ARCH SMP preempt mod_unload '
vboxdrv: version magic '5.2.0-arch2-1-ARCH SMP preempt mod_unload ' should be '5.1.15-arch1-1-ARCH SMP preempt mod_unload '
bbswitch: version magic '5.2.0-arch2-1-ARCH SMP preempt mod_unload ' should be '5.1.15-arch1-1-ARCH SMP preempt mod_unload '
nvidia: version magic '5.2.0-arch2-1-ARCH SMP preempt mod_unload ' should be '5.1.15-arch1-1-ARCH SMP preempt mod_unload '

Originally Posted by MarioMaster100 I have a few module issues I'm not sure how to fix.

You will have to rebuild the VBox kernel modules (like vboxdrv) against the sources of that older kernel. This goes too for nVidia proprietary ones and any other modules that are not included IN the kernel source.
BTW: this is true too when you UPgrade the kernel, the modules are version-specific.

I'm not quite sure what the proper procedure to build a kernel on arch linux is. I tried getting the lts kernel, headers, nvidia-lts and that was fine but I also needed the bbswitch-lts and virtualbox lts packages which won't build because they require an older lts kernel.

Ok I finally figured it out, the lts kernel did work I just needed the dkms packages for my modules.