The HTML page was very crappy.  There were two text entry widgets - the first
one was supposed to be what the name of the workspace to import to is, and the
second one the filename.  Neither were labeled.

Now at the same level as in a lot of places - know what the error to catch is
(in case they leave a field blank) but unclear on how to handle it.

I confirm that this one actually happens here locally.  Will see what is going
on ....

Even when you use a text file containing the XML provided by export workspace,
you get an error.  Here is the traceback:

Site Error

An error was encountered while publishing this resource.

BadRequest

Sorry, a site error occurred.
Traceback (innermost last):

Module ZPublisher.Publish, line 188, in publish_module_standard
Module ZPublisher.Publish, line 145, in publish
Module Zope2.App.startup, line 222, in zpublisher_exception_hook
Module ZPublisher.Publish, line 114, in publish
Module ZPublisher.mapply, line 88, in mapply
Module ZPublisher.Publish, line 40, in call_object
Module Products.SGDI.SGDI, line 1052, in importWorkspace
Module Products.SGDI.SGDI, line 989, in addWorkspace
Module Products.SGDI.SGDIworkspace, line 16, in manage_addSGDIworkspace
Module Products.SGDI.SGDIworkspace, line 30, in __init__
Module OFS.Image, line 57, in manage_addFile
Module OFS.ObjectManager, line 297, in _setObject
Module OFS.ObjectManager, line 73, in checkValidId
BadRequest: ('Empty or invalid id specified', '') (Also, the following error
occurred while attempting to render the standard error message, please see the
event log for full details: You are not allowed to access 'title_or_id' in this
context)

Click on Import workspace.  Use file dialog to select any random file, say a
pdf.  Click submit.  Poof.