Traceback (most recent call last):
  File "/usr/local/bin/vimwiki_markdown", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.9/dist-packages/vimwiki_markdown.py", line 148, in main
    content = md.convert(content)
  File "/usr/local/lib/python3.9/dist-packages/markdown/core.py", line 268, in convert
    newRoot = treeprocessor.run(root)
  File "/usr/local/lib/python3.9/dist-packages/markdown/extensions/footnotes.py", line 372, in run
    footnotesDiv = self.footnotes.makeFootnotesDiv(root)
  File "/usr/local/lib/python3.9/dist-packages/markdown/extensions/footnotes.py", line 179, in makeFootnotesDiv
    self.parser.parseChunk(surrogate_parent, self.footnotes[id])
  File "/usr/local/lib/python3.9/dist-packages/markdown/blockparser.py", line 105, in parseChunk
    self.parseBlocks(parent, text.split('\n\n'))
  File "/usr/local/lib/python3.9/dist-packages/markdown/blockparser.py", line 123, in parseBlocks
    if processor.run(parent, blocks) is not False:
  File "/usr/local/lib/python3.9/dist-packages/markdown_verse/extension.py", line 69, in run
    el.text += '\n\n'
AttributeError: 'NoneType' object has no attribute 'text'