VirtualBox in antiX-19 Main will be upgraded to version 6.1.2 tomorrow, 2/6/2020. There have been a number of bugfixes and improvements since the current version, and the current version will not build its modules on the new 5.4+ version kernels so this update is necessary,
VirtualBox users need to know that any Saved or Paused VMs will not open after a VirtualBox version update. Here are your options to avoid trouble:
1) Shutdown the OS in any VMs you have before you upgrade.
or
2) Lock your current VirtualBox version so it won’t upgrade.
sudo apt-mark hold virtualbox*
If you also do updates with Synaptic you will need to lock the virtualbox packages there as well since it ignores apt-mark hold and apt-get ignores Synaptic’s package locks.
If you have already upgraded you have two options to repair.
A) If the saved state of the VM is not important to you, you can use the Discard Saved State… option in the settings for that VM and it should start up.
B) If the saved state is important you can reinstall your old Virtualbox packages from /var/cache/apt/archives, then follow 1) or 2) above.