Safari Extension: Please make sure your manifest.json file contains valid syntax

This is my manifest.json file for my safari extension that I've just developed:

{
  "manifest_version": 2,
  "default_locale": "en",
  "name": "BeTimeful",
  "description": "Never regret going to social media or YouTube again!",
  "version": "1.0",
  "icons": {
    "48": "images/icon-48.png",
    "64": "images/icon-64.png",
    "96": "images/icon-96.png",
    "128": "images/icon-128.png",
    "256": "images/icon-256.png",
    "512": "images/icon-512.png"
  },
  "web_accessible_resources": ["images/*", "*"],
  "browser_action": {
    "default_popup": "popup/index.html",
    "default_title": "Betimeful",
    "default_icon": {
      "16": "images/toolbar-icon-16.png",
      "19": "images/toolbar-icon-19.png",
      "32": "images/toolbar-icon-32.png",
      "38": "images/toolbar-icon-38.png",
    }
  },
  "background": {
    "scripts": ["Libraries/jquery.js","Libraries/raygun.min.js", "js/background.js"],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.betimeful.com/cancel",
        "*://www.betimeful.com/success"
      ],
      "js": ["js/success.js"]
    },
    {
      "matches": ["*://calendar.google.com/*", "http://blank.org/*"],
      "js": [
        "Libraries/jquery.js",
        "Libraries/party.min.js",
        "Libraries/popper.min.js",
        "Libraries/bootstrap.min.js",
        "Libraries/purify.min.js",
        "js/quotes.js",
        "js/html.js",
        "js/content.js",
        "js/actions.js"
      ],
      "run_at": "document_start",
      "css": [
        "styles/content.css",
        "styles/Socialstyles.css",
        "styles/bootstrap.min.css"
      ]
    },
    {
      "matches": [
        "*://www.facebook.com/*",
        "*://www.instagram.com/*",
        "*://www.linkedin.com/*",
      ],
      "run_at": "document_start",
      "js": ["Libraries/jquery.js","Libraries/raygun.min.js","Libraries/purify.min.js", "js/quotes.js", "js/social_handler.js"]
    },
    {
      "matches": [
        "https://www.facebook.com/"
      ],
      "run_at": "document_start",
      "js": ["Libraries/jquery.js", "js/freemium.js"]
    }
  ],
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "cookies",
    "*://betimeful.com/*",
    "*://www.betimeful.com/*",
    "https://api.mixpanel.com/*",
  ]
}

When I git publish/distribute app, I get:

Corrupted manifest file. The manifest.json file could not be read in Safari extension bundle BeTimefulSafari.app/Contents/PlugIns/BeTimefulSafari Extension.appex. Please make sure your manifest.json file contains valid syntax. With error code STATE_ERROR.VALIDATION_ERROR.90848 for id c549-f7-4ef-a52a-20bb

I am not sure what's wrong with it as the same manifest works well with the chrome extension that's live in the chrome store nor have I seen any solutions on the web.

Appreciate the help.