Traceback (most recent call last):
        20: from C:/bin/Ruby26-x64/bin/asciidoctor-pdf:23:in `<main>'
        19: from C:/bin/Ruby26-x64/bin/asciidoctor-pdf:23:in `load'
        18: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-pdf-1.5.0.beta.2/bin/asciidoctor-pdf:32:in `<top (required)>'
        17: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/cli/invoker.rb:111:in `invoke!'
        16: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/cli/invoker.rb:111:in `each'
        15: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/cli/invoker.rb:128:in `block in invoke!'
        14: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:183:in `convert_file'
        13: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:183:in `open'
        12: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:183:in `block in convert_file'
        11: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:118:in `convert'
        10: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/document.rb:951:in `convert'
         9: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-pdf-1.5.0.beta.2/lib/asciidoctor-pdf/converter.rb:134:in `convert'
         8: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-pdf-1.5.0.beta.2/lib/asciidoctor-pdf/converter.rb:260:in `convert_document'
         7: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-pdf-1.5.0.beta.2/lib/asciidoctor-pdf/converter.rb:150:in `convert_content_for_block'
         6: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/document.rb:1020:in `content'
         5: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/abstract_block.rb:84:in `content'
         4: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/abstract_block.rb:84:in `map'
         3: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/abstract_block.rb:84:in `block in content'
         2: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-2.0.10/lib/asciidoctor/abstract_block.rb:75:in `convert'
         1: from C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-pdf-1.5.0.beta.2/lib/asciidoctor-pdf/converter.rb:134:in `convert'
C:/bin/Ruby26-x64/lib/ruby/gems/2.6.0/gems/asciidoctor-pdf-1.5.0.beta.2/lib/asciidoctor-pdf/converter.rb:666:in `convert_admonition': undefined method `[]' for nil:NilClass (NoMethodError)