0.8.49 won't convert like previous versions

[Dickison]

I've made about 100 ebooks using previous versions and had no problems. Doing nothing different on this one, which is my first conversion using 0.8.49, I got the following error. I usually take a Word document, save it as HTML, load that into Calibre and convert. Not so this time. Can someone tell me what the problem is from all the stuff below?

Thanks.


calibre, version 0.8.49
ERROR: Conversion Error: <b>Failed</b>: Convert book 1 of 1 (The Listener)

Spoiler:

Convert book 1 of 1 (The Listener)
Processing archive...
Resolved conversion options
calibre version: 0.8.49
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'breadth_first': False,
'change_justification': u'justify',
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., 'chapter|book|section|part|prologue|epilogue\\s+', 'i')) or @class = 'chapter']",
'chapter_mark': u'pagebreak',
'comments': None,
'cover': None,
'debug_pipeline': None,
'dehyphenate': True,
'delete_blank_paragraphs': True,
'disable_font_rescaling': False,
'dont_compress': False,
'dont_package': False,
'duplicate_links_in_toc': False,
'enable_heuristics': False,
'extra_css': None,
'extract_to': None,
'filter_css': u'',
'fix_indents': True,
'font_size_mapping': None,
'format_scene_breaks': True,
'html_unwrap_factor': 0.4,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.MobipocketInput object at 0x1085d86d0>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': False,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': False,
'language': None,
'level1_toc': u'//h:h1',
'level2_toc': u'//h:h2',
'level3_toc': u'//h:h3',
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'markup_chapter_headings': True,
'max_levels': 5,
'max_toc_links': 125,
'minimum_line_height': 120.0,
'mobi_ignore_margins': False,
'mobi_keep_original_images': False,
'mobi_toc_at_start': True,
'no_chapters_in_toc': False,
'no_inline_navbars': False,
'no_inline_toc': False,
'output_profile': <calibre.customize.profiles.OutputProfile object at 0x1085d8890>,
'page_breaks_before': u"//*[name()='h1' or name()='h2']",
'personal_doc': u'[PDOC]',
'prefer_author_sort': False,
'prefer_metadata_cover': False,
'pretty_print': False,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': u'/var/folders/zf/n0p5f_jn1cng9gjgrvwszq1w0000gq/T/calibre_0.8.49_tmp_45ecg7/oo7mb8.opf',
'remove_fake_margins': True,
'remove_first_image': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'renumber_headings': True,
'replace_scene_breaks': u'',
'search_replace': '[]',
'series': None,
'series_index': None,
'share_not_sync': False,
'smarten_punctuation': False,
'sr1_replace': None,
'sr1_search': None,
'sr2_replace': None,
'sr2_search': None,
'sr3_replace': None,
'sr3_search': None,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 99,
'toc_title': None,
'unsmarten_punctuation': False,
'unwrap_lines': True,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: HTML Input running
on /var/folders/zf/n0p5f_jn1cng9gjgrvwszq1w0000gq/T/calibre_0.8.49_tmp_45ecg7/lbctuv_plumber_archive/content.opf
Parsing all content...
Manifest item 'toc.ncx' not found
Parsing The Listener.htm ...
Found microsoft markup, cleaning...
Generating default TOC from spine...
Merging user specified metadata...
Detecting structure...
Auto generated TOC with 9 entries.
Python function terminated unexpectedly: All strings must be XML compatible: Unicode or ASCII, no NULL bytes
Flattening CSS and remapping font sizes...
Source base font size is 12.00000pt
Traceback (most recent call last):
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.7/site.py", line 147, in main
return run_entry_point()
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.7/site.py", line 116, in run_entry_point
return getattr(pmod, func)()
File "site-packages/calibre/utils/ipc/worker.py", line 191, in main
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 31, in gui_convert_override
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 25, in gui_convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 1065, in run
File "site-packages/calibre/ebooks/oeb/transforms/flatcss.py", line 147, in __call__
File "site-packages/calibre/ebooks/oeb/transforms/flatcss.py", line 435, in flatten_spine
File "site-packages/calibre/ebooks/oeb/transforms/flatcss.py", line 409, in flatten_head
File "lxml.etree.pyx", line 821, in lxml.etree._Element.text.__set__ (src/lxml/lxml.etree.c:33308)
File "apihelpers.pxi", line 646, in lxml.etree._setNodeText (src/lxml/lxml.etree.c:15287)
File "apihelpers.pxi", line 1295, in lxml.etree._utf8 (src/lxml/lxml.etree.c:20212)
ValueError: All strings must be XML compatible: Unicode or ASCII, no NULL bytes

[theducks]

The last line says it:
Null (x00) characters detected in XML.
Your source is defective.