I mean before this started happening.
Nope. All ways ran shutdown -h now. Unless a power outage counts.
That could cause this kind of error (on any OS). If you boot the VM and while its booting hit the Shift key you can get to the grub menu to boot it into recovery mode (unless you disabled it).
That happened months ago though.
Still having problems getting mine to boot 
Did you follow the guide that I linked in your post?
Hey! Im kinda new. The times I get IO errors are when I use virtio as a virtual storage controller. Using anything virtio hates me.
I personally have had mixed experiences with virtip (with ProxMox) on my SolusVM machine(s) it seems to work well (thus far). But I haven’t had the errors that @MyPlaceOnYT is/was experiencing.
Never mind. I read a tutorial that said you have to rename the .iso to raw and it booted right away!