Thought I would include a bit more info from my post above on how to fix this, following VeeDubb65's advice
Open the properties of the MiVoice Business Software Installer and look at the target, it should be something similar to:
"
C:\Program Files (x86)\Mitel\MiVoice Business Software Installer\jre\bin\javaw.exe" -classpath "..\lib;..\..\lib\SoftwareInstaller.jar" -DSI_HOME="%SI_HOME%" autoinstaller.AI_Main_Controller
I have placed the text in bold that needs to be replaced. Make sure you have an up to date version of Java installed on your machine, go to the folder in the Java installation which contains the "javaw.exe" file. Copy this path (it should be similar to the following: C:\Program Files\Java\jre1.8.0_144\bin) and replace this in the target.
The new target should now be:
"C:\Program Files\Java\
jre1.8.0_144\bin\javaw.exe" -classpath "..\lib;..\..\lib\SoftwareInstaller.jar" -DSI_HOME="%SI_HOME%" autoinstaller.AI_Main_Controller
(note the bold bit will differ depending on java version you have installed)
Start the program up and it should no longer crash on the retrieve license section
