Narou.rb のバージョン：Narou.rb version 3.2.3
OS のバージョン：Windows 10 Pro
その他環境情報（任意）：ruby 2.5.1p57
何が起きたのか：［蜘蛛ですが、なにか？］の変換に失敗します。
再現方法（何をやったら起こったのか詳細に）：
WEB UI上から失敗しましたので、コマンドも試しましたが下記の通りエラーになりました。
narou --backtrace convert n7975cr
ID:2661 蜘蛛ですが、なにか？ の変換を開始
C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/inspector.rb:183:in `block in countup_return_in_brackets': undefined method `scan' for #<Array:0x03910428> (NoMethodError)
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/inspector.rb:182:in `each'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/inspector.rb:182:in `countup_return_in_brackets'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/novelconverter.rb:723:in `inspect_novel'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/novelconverter.rb:394:in `convert_main'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/novelconverter.rb:51:in `convert'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:208:in `block in convert_novels'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:181:in `each'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:181:in `with_index'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:181:in `convert_novels'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:162:in `block in execute'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:155:in `each'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/command/convert.rb:155:in `execute'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/commandline.rb:46:in `run'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/narou.rb:48:in `block in <top (required)>'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/lib/backtracer.rb:16:in `capture'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/narou.rb:47:in `<top (required)>'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/bin/narou:13:in `require_relative'
from C:/Ruby25/lib/ruby/gems/2.5.0/gems/narou-3.2.3/bin/narou:13:in `<top (required)>'
from C:/Ruby25/bin/narou:23:in `load'
from C:/Ruby25/bin/narou:23:in `<main>'
※ Narou.rb version 3.1.11 の環境が別PCに残っていたので試したところ、そちらでは変換に成功しました。
