[Ronin2009]

I downloaded a pdf from the "Instructables" site. It is an instructable about building a catamaran SUP. The conversion finished quickly with no error listed, but when I click the "epub" link in Calibre to view the file, I get an error (details between asterisks).
*******
Traceback (most recent call last):
File "/usr/lib/calibre/calibre/gui2/viewer/main.py", line 38, in run
Thread.run(self)
File "/usr/lib/python2.7/threading.py", line 505, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/lib/calibre/calibre/ebooks/oeb/iterator/book.py", line 173, in __enter__
create_indexing_data(self.spine, self.toc)
File "/usr/lib/calibre/calibre/ebooks/oeb/iterator/spine.py", line 103, in create_indexing_data
(i-1 for i, t in enumerate(toc.flat()) if t is not toc)
File "/usr/lib/calibre/calibre/ebooks/oeb/iterator/spine.py", line 65, in __init__
self.spine_pos = spine.index(self.key)
ValueError: '/member/mayala6/' is not in list
*******
The pdf was an instructable created by a user named "mayala6" and on the 1st page of the PDF, as in all Instructable PDFs is a web link to the users area on the Instructables site. That seems to be the "ValueError". Is this somethin that can be easily fixed or am I just hosed?
Thanks for any help.