Windows phone development

Hi,

I'm trying to start with Windows phone development. For that I use a Windows 8.1 - 64 bits virtual machine.

But I get several errors

1) When I launch appcelerator studio I get this two errors :

An internal error occurred during: "Computing SDK Info...". com.appcelerator.titanium.core.TitaniumCorePlugin.getCLI()Lcom/appcelerator/titanium/core/cli/ITitaniumCLI;

And

An internal error occurred during: "Initializing Windows Core Plugin". com.appcelerator.titanium.core.TitaniumCorePlugin.getCLI()Lcom/appcelerator/titanium/core/cli/ITitaniumCLI;

2) When I choose a Titanium SDK greater than 4.0.X I get this error :

An internal error occurred during: "Retrieving platform status...". com.appcelerator.titanium.core.TitaniumCorePlugin.getCLI()Lcom/appcelerator/titanium/core/cli/ITitaniumCLI;

And a smaller SDK "does not support Windows development"...

Configuration : Appcelerator Studio, build: 4.0.1.201506120914

Can someone help me ?

Don't hesitate to ask me for more information

Thanks in advance,

Arnaud