I was trying to use Gibbed’s Mass Effect 3 Audio Extractor recently, but it failed with:

IO.Path.Combine path1 cannot be null

To fix this, use regedit to go to

• HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\BioWare\Mass Effect 3 (on 64 bit machines)
• HKEY_LOCAL_MACHINE\SOFTWARE\BioWare\Mass Effect 3 (on 32 bit machines)

Add a new registry entry (right click -> “New” -> “String Value”). Name it Install Dir. Set the value to your installation directory (the same value as the Path registry entry). Close regedit. Re-open Gibbed’s Mass Effect 3 Audio Extractor.