Recently I updated my kde neon installation. After the installation was complete it said a restart was required. When I rebooted I saw the following message:
0.149184] Bios Error (bug): Failure creatring named object [\_SB.SMIC] , AE_Already_Exists (20190816/dswload2-326)
0.149202] ACPI Error: AE_Already_Exists, During name Lookup/catalog (20190816/psobject-220)
0.149207] ACPI Bios Error (bug): Failure creating named object [\_SB.SMIB] , AE_Already_Exists (20190816/dsfield-638)
0.226255] pci 0000:00:00.2: AMD-VI: Unable to read/write to IOMMU perf counter.
[ OK } Finished Terminate Plymouth Boot Screen.

I am using an AMD B450 Pro4 motherboard and virtualization support is turned on in the bios. The above error message was only displayed once now all I get is a black screen when I boot the pc. If I reboot the pc once things stop I can crtl-alt-F2 and get to a new log in prompt. I can log in and even start the desktop with startx. However there is no network connection so I can't use apt to fix the upgrade. Is there anyway to recover from this without reinstalling the os? Also I'm not sure if it's the os or the motherboard but I don't see the grub splash screen if I hold the shift key down during boot.
Thanks for any help.