I got the following memory error randomly more and more. However, I don't recall, I did something differently from my daily work. Aside that I remote desktop to my computer nowadays.
VirtualBoxVM.exe - Application Error
The instruction at 0x00007FFF7FE0C222 referenced memory at 0x0000000000000000. The memory could not be read.
Solution
I upgraded from VirtualBox-6.0.16-135674-Win.exe to VirtualBox-6.1.4-136177-Win.exe. The random memory error doesn't seem come back. I have been using the new version for more than a week now.