virtualbox.org

I am using VirtualBox 4.3.0 and all the information on my guests is missing - it's saying 'Information Inaccessible'.
I can't run them either - NS_CALL_ERROR(sorry if I've got it wrong). And when I go into Settings, I get a blank window(except for 'Cancel' and 'Ok', which don't work). Any answers

1. With VirtualBox running and the error displayed
2. start up application Activity Monitor, located in /Applications/Utilities folder
3. In the ToolBar, select All Processes
4. Click on Process Names in the Column Headings to get an alphabetized list
5. Scroll down and locate these processes/daemons
   • VirtualBox
   • VBoxXPCOMIPCD
   • VBoxSVC
6. If VBoxSVC process/daemon is missing, the error you describe will occur
7. And you need to gather diagnostic data

To gather the diagnostic data, refer to Minimum information needed for assistance

Curiosity: were you trying to access an USB device in a Virtual Machine?

Looking at Activity Monitor:
The VBoxSVC process appears when VirtualBox is opening, but crashes when it is opened - I think that's what's causing the problem.
P.S. I can't open any VMs.