Had the same issue with 4.4.0-143.
First, I upgraded VirtualBox to 5.2, which didn't help. So, I reverted back to 5.1.138. Still, no luck.
I then booted into kernel 4.4.0-142 and that fixed the problem.
Had the same issue with 4.4.0-143.
First, I upgraded VirtualBox to 5.2, which didn't help. So, I reverted back to 5.1.138. Still, no luck.
I then booted into kernel 4.4.0-142 and that fixed the problem.