In this case, a customer reported that the Add to Menu list in the Command Wizard was empty. Normally, Add to Menu lists all anchor points for menus where you can add a custom command, but now it had just one entry: None.
The SDK wizards are JScript plugins, so it wasn’t hard to track down where things were going wrong. The Add to Menu list is built by parsing a header file (xsi_decl.h):
var oFSO = new ActiveXObject( "Scripting.FileSystemObject" ) ;
strFactoryPath = Application.InstallationPath( siFactoryPath ) ;
strDeclFile = XSIUtils.BuildPath(XSIUtils.Environment("XSISDK_ROOT"),"include","xsi_decl.h") ;
Based on this, it didn’t take to long to figure out the problem: the customer was starting Softimage with a shortcut to XSI.exe, so setenv.bat was never called, and XSISDK_ROOT was never set.
XSI.bat is the way to start Softimage. XSI.bat calls setenv.bat to set all the required environment variable, and then starts XSI.exe.
eX-SI 
Another occurrence of the “missing anchors”: the Autodesk Softimage Mod Tool 7.5 😉
…even if it’s correctly started using the bat-file…
I don’t think the Mod Tool includes the SDK, so there’s no xsi_decl.h file in the distribution.
So, no Add to Menu list.
You can however still do basic scripting with it & the sdk docs are included… 😉
It’s not a big deal, obviously, just something a noticed recently, when I tried to whip up a simple script and only had the Mod Tool at hand…
Yup, you get “in-product scripting”, but you don’t get the includes and libs necessary to do compiled plugins.