Can anybody help me?

[NullPointerException]

Failed to open a session for the virtual machine Lab VM.

The virtual machine 'Lab VM' has terminated unexpectedly during startup with exit code 1.

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

Can anybody help me? I am a programmer, but it hurts my head to think about this error. Why and how it caused, how to fix it?

[mpack]

See the "4.3.14 conflicts with anti-virus" sticky discussion at the top of this forum. Make sure you read the first post.

Or, revert to 4.3.12.

Edit:  Note: nowhere did I say that you yourself had an anti-virus problem. The topic title is designed to meet the most common case.