Virtualbox returning errorID=BLKCACHE_IOERR
I ended up finding a fix with the help of antiduh:
I cloned my old vdi into a new vdi using: VBoxManage clonehd Linux.vdi LinuxClone.vdi
Once that happened I opened up VirtualBox and created a new VM and when it came to the Hard Disk section, instead of creating a new virtual disk I selected my existing LinuxClone.vdi file and when I started it up, it ran! I got the idea from this article.
The solution is simply to enable the cache I/O host. It can be activated in the configuration of the machine, Storage »SATA Controller" Use the cache I/O host (all other values are those used by default VirtualBox). After this change the error disappears
I actually ran into this problem because the disk, where I save all my VM disks, was full. So I cleared some space and I was able to resume the VM.