Unable to run wsimport on wsdl

[Guest]

I'm trying to import the wsdl using Java's wsimport, however its throwing up some errors. Any idea what the cause might be? Is the wsdl definitely valid?

C:\Java\workspace\buildmaster-plugin>%JAVA_HOME%\bin\wsimport wsdl\BuildMaster.wsdl
parsing WSDL...


[WARNING] src-resolve.4.2: Error resolving component 's:schema'. It was detected that 's:schema' is in
 namespace 'http://www.w3.org/2001/XMLSchema', but components from this namespace are not referenceable 
 from schema document 'file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl#types?schema1'. 
 If this is the incorrect namespace, perhaps the prefix of 's:schema' needs to be changed. If this is the 
 correct namespace, then an appropriate 'import' tag should be added to 
 'file:/C:/Java/workspace/buildmasterplugin/wsdl/BuildMaster.wsdl#types?schema1'.
  line 128 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl#types?schema1

[WARNING] src-resolve: Cannot resolve the name 's:schema' to a(n) 'element declaration' component.
  line 128 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl#types?schema1

[ERROR] undefined element declaration 's:schema'
  line 128 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl

[ERROR] undefined element declaration 's:schema'
  line 150 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl

[ERROR] undefined element declaration 's:schema'
  line 172 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl

[ERROR] undefined element declaration 's:schema'
  line 217 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl

# [ERROR] undefined element declaration 's:schema'  
  line 455 of file:/C:/Java/workspace/buildmaster-plugin/wsdl/BuildMaster.wsdl #

etc

Product: BuildMaster
Version: 4.5.6

[Guest]

I'm not sure what the tool is validating exactly, but after uploading the WSDL file to https://www.wsdl-analyzer.com, it said the document was valid.

I am not super familiar with Java or any Java tools, but the same problem looks like it has occurred here: http://stackoverflow.com/questions/13499860/jax-ws-error-on-wsdl-file-error-resolving-component-sschema