In order to import this specific wsdl, the wizard needs to update the package XML/www.w3.org/2001/XMLSchema, which is included in the common library and thus read-only by default. The wizard cannot at present update read-only packages - see bug #430.
We don't expect to handle this issue in the near future, but you can workaround it by manually creating a local copy of the relevant packages, using the following procedure:
Now retry importing your WSDL.
Note that this method has one drawback, being that if we make any future updates to the common library packages which have a local copy, they will not be available to this project.
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