gitbook serveができない

タイトルの通り、gitbook serveができなくて困っています。。
どなたか助けていただけないでしょうか。

//エラー内容

gitbook serve                                                                                                   
Live reload server started on port: 35729
Press CTRL+C to quit ...

info: 16 plugins are installed 
info: 15 explicitly listed 
info: loading plugin "graph"... OK 
info: loading plugin "mermaid-gb3"... OK 
info: loading plugin "uml"... ERROR

PluginError: Error with plugin "uml": Unexpected token {

＜試したこと＞

各コマンドでnode_modulesとpackage-lock.jsonを消してキャッシュをクリアにし、

再度npmをインストール

rm -rf node_modules && rm package-lock.json && npm cache clear --force && npm cache clean --force && npm install

ちなみにgitbook installは問題なくできています

gitbook install 
                                                                                                
info: installing 8 plugins using npm@3.9.2 
info:  
info: installing plugin "graph" 
info: install plugin "graph" (*) from NPM with version 0.1.0 
info: >> plugin "graph" installed with success 
info:  
info: installing plugin "mermaid-gb3" 
info: install plugin "mermaid-gb3" (*) from NPM with version 2.1.0 
info: >> plugin "mermaid-gb3" installed with success 
info:  
info: installing plugin "uml" 
info: install plugin "uml" (*) from NPM with version 1.2.1 
info: >> plugin "uml" installed with success 
info:  
info: installing plugin "simple-page-toc" 
info: install plugin "simple-page-toc" (*) from NPM with version 0.1.2 
info: >> plugin "simple-page-toc" installed with success 
info:  
info: installing plugin "theme-api" 
info: install plugin "theme-api" (*) from NPM with version 1.1.2 
info: >> plugin "theme-api" installed with success 
info:  
info: installing plugin "collapsible-menu" 
info: install plugin "collapsible-menu" (*) from NPM with version 1.0.3 
info: >> plugin "collapsible-menu" installed with success 
info:  
info: installing plugin "expandable-chapters" 
info: install plugin "expandable-chapters" (*) from NPM with version 0.2.0 
info: >> plugin "expandable-chapters" installed with success 
info:  
info: installing plugin "katex" 
info: install plugin "katex" (*) from NPM with version 1.1.4 
info: >> plugin "katex" installed with success

//package.json

{
  "name": "ligua",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "config": {},
  "scripts": {
    "init": "$(npm bin)/gitbook init",
    "install": "$(npm bin)/gitbook install",
    "serve": "$(npm bin)/gitbook serve",
    "build": "$(npm bin)/gitbook build",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "d3-graphviz": "^3.1.0",
    "gitbook-api": "^3.0.2",
    "gitbook-cli": "^2.3.0",
    "gitbook-plugin-collapsible-menu": "^1.0.3",
    "gitbook-plugin-expandable-chapters": "^0.2.0",
    "gitbook-plugin-graph": "^0.1.0",
    "gitbook-plugin-katex": "^1.1.4",
    "gitbook-plugin-mermaid-gb3": "^2.0.0",
    "gitbook-plugin-theme-api": "^1.1.2",
    "gitbook-plugin-toc": "0.0.2",
    "gitbook-plugin-uml": "^0.1.6"
  }
}