This is my current configuration:
You have a couple of problems here.
First, the XSD has an issue where an element is both named or referenced; in your case should be referenced.
Change:
To:
And:
StockStockSo:
To:
Make sure you fix the xml closing tags.
The second problem is that the correct way to reference an external XSD is to use XSD schema with import/include within a wsdl:types element. wsdl:import is reserved to referencing other WSDL files. More information is available by going through the WS-I specification, section WSDL and Schema Import. Based on WS-I, your case would be:
INCORRECT: (the way you showed it)
CORRECT:
SOME processors may support both syntaxes. The XSD you put out shows issues, make sure you first validate the XSD.
It would be better if you go the WS-I way when it comes to WSDL authoring.
Other issues may be related to the use of relative vs. absolute URIs in locating external content.