Popular Science fails

[duluoz]

Error message below:

calibre, version 4.20.0 (linux2, embedded-python: True)
Conversion error: Failed: Fetch news from Popular Science

Fetch news from Popular Science
Conversion options changed from defaults:
  verbose: 2
  output_profile: u'kindle_pw3'
Resolved conversion options
calibre version: 4.20.0
{'asciiize': False,
 'author_sort': None,
 'authors': None,
 'base_font_size': 0,
 'book_producer': None,
 'change_justification': u'original',
 'chapter': None,
 '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_download_recipe': False,
 'duplicate_links_in_toc': False,
 'embed_all_fonts': False,
 'embed_font_family': None,
 'enable_heuristics': False,
 'expand_css': False,
 'extra_css': None,
 'extract_to': None,
 'filter_css': None,
 'fix_indents': True,
 'font_size_mapping': None,
 'format_scene_breaks': True,
 'html_unwrap_factor': 0.4,
 'input_encoding': None,
 'input_profile': <calibre.customize.profiles.InputProfile object at 0x7f62df573610>,
 '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': None,
 'level2_toc': None,
 'level3_toc': None,
 'line_height': 0,
 'linearize_tables': False,
 'lrf': False,
 'margin_bottom': 5.0,
 'margin_left': 5.0,
 'margin_right': 5.0,
 'margin_top': 5.0,
 'markup_chapter_headings': True,
 'max_toc_links': 50,
 'minimum_line_height': 120.0,
 'mobi_file_type': u'old',
 'mobi_ignore_margins': False,
 'mobi_keep_original_images': False,
 'mobi_toc_at_start': False,
 'no_chapters_in_toc': False,
 'no_inline_navbars': True,
 'no_inline_toc': False,
 'output_profile': <calibre.customize.profiles.KindlePaperWhite3Output object at 0x7f62df573e10>,
 'page_breaks_before': None,
 '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': None,
 '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': None,
 'series': None,
 'series_index': None,
 'share_not_sync': False,
 'smarten_punctuation': False,
 'sr1_replace': u'',
 'sr1_search': u'',
 'sr2_replace': u'',
 'sr2_search': u'',
 'sr3_replace': u'',
 'sr3_search': u'',
 'start_reading_at': None,
 'subset_embedded_fonts': False,
 'tags': None,
 'test': False,
 'timestamp': None,
 'title': None,
 'title_sort': None,
 'toc_filter': None,
 'toc_threshold': 6,
 'toc_title': None,
 'transform_css_rules': None,
 'unsmarten_punctuation': False,
 'unwrap_lines': True,
 'use_auto_toc': False,
 'verbose': 2}
InputFormatPlugin: Recipe Input running
Downloading recipe urn: builtin:popscience
Trying to get latest version of recipe: popscience
Using user agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36
Traceback (most recent call last):
  File "site.py", line 77, in main
  File "site-packages/calibre/utils/ipc/worker.py", line 209, in main
  File "site-packages/calibre/gui2/convert/gui_conversion.py", line 36, in gui_convert_recipe
  File "site-packages/calibre/gui2/convert/gui_conversion.py", line 28, in gui_convert
  File "site-packages/calibre/ebooks/conversion/plumber.py", line 1110, in run
  File "site-packages/calibre/customize/conversion.py", line 246, in __call__
  File "site-packages/calibre/ebooks/conversion/plugins/recipe_input.py", line 139, in convert
  File "site-packages/calibre/web/feeds/news.py", line 1028, in download
  File "site-packages/calibre/web/feeds/news.py", line 1196, in build_index
  File "<string>", line 36, in parse_index
TypeError: coercing to Unicode: need string or buffer, NoneType found

[kovidgoyal]

https://github.com/kovidgoyal/calibr...d5f977c89809ad