Failed open session

[falens]

hi,

after upgraded from VB 4.3.6 to 4.3.20, all my machine were I created before can't work, even if I create new again, always display error message, e.g from 1 machine :

Failed to open a session for the virtual machine Microsoft Windows XP Professional SP3 x86 Dec 2014.

The virtual machine 'Microsoft Windows XP Professional SP3 x86 Dec 2014' has terminated unexpectedly during startup with exit code 1 (0x1). More details may be available in 'D:\Virtualbox\Microsoft Windows XP Professional SP3 x86 Dec 2014\Logs\VBoxStartup.log'.

Result Code: E_FAIL (0x80004005)
Component: Machine
Interface: IMachine {480cf695-2d8d-4256-9c7c-cce4184fa048}

could someone can tell me to fix this ?

thank you

[mpack]

You could start by posting a zipped copy of the startup log mentioned.

Also review the "security issues" discussion the top of this forum (that's also where you should post the log).

Reverting to 4.3.12 is the short term fix.