Error: Invalid store [fslookup], allowed values are

[Raathigesh]

I'm trying to get the coverage configured for a React + Typescript + Webpack project. I'm following the instruction from here. But when Html report is configured in remap-instalbul, the following error occurs.

Any pointers would be helpful.

Error: Invalid store [fslookup], allowed values are
    at Object.Factory.create (E:\APPS\node_modules\remap-istanbul\node_modules\istanbul\lib\util\factory.js:47:28)
    at new HtmlReport (E:\APPS\node_modules\remap-istanbul\node_modules\istanbul\lib\report\html.js:350:15)
    at E:\APPS\node_modules\remap-istanbul\lib\writeReport.js:76:20
    at E:\APPS\node_modules\amdefine\amdefine.js:125:34
    at nextTickCallbackWith0Args (node.js:453:9)
    at process._tickCallback (node.js:382:13)

Karma config with Webpack configuration:

module.exports = function (config) {
  config.set({
    basePath: '',
    frameworks: ['mocha', 'chai', 'sinon', 'source-map-support'],
    files: [
      './shell/apps/**/*.spec.tsx'
    ],
    plugins: ["karma-*"],
    preprocessors: {
      './shell/apps/**/.tsx': ['webpack', 'sourcemap', 'coverage'],
      './shell/apps/**/*.spec.tsx': ['webpack']
    },
    webpack: {
      devtool: 'inline-source-map',
      module: {
        loaders: [
          {
            test: /\.(ts|tsx)$/,
            exclude: /node_modules/,
            loader: 'awesome-typescript-loader'
          },
          {
            test: /\.json$/,
            loader: 'json'
          },
          {
            test: /\.((woff2?|svg)(\?v=[0-9]\.[0-9]\.[0-9]))|(woff2?|svg|jpe?g|png|gif|ico)$/,
            loader: 'url?limit=10000'
          }
        ],
        postLoaders: [
          /**
           * Instruments TS source files for subsequent code coverage.
           * See https://github.com/deepsweet/istanbul-instrumenter-loader
           */
          {
            test: /\.(ts|tsx)$/,
            loader: 'istanbul-instrumenter-loader',
            exclude: [
              /node_modules/,
              /tests/,
              /\.(e2e|spec)\.tsx$/
            ]
          }
        ]
      },
      resolve: {
        //Added .json extension required by cheerio (enzyme dependency)
        extensions: ['', '.js', '.ts', '.tsx', '.json']
      },
      //Configuration required by enzyme
      externals: {
        'react/lib/ExecutionEnvironment': true,
        'react/lib/ReactContext': 'window',
        'cheerio': 'window',
        'react/addons': true,
      }
    },
    /**
     * Make dev server silent.
     */
    webpackServer: { noInfo: true },
    reporters: ['progress', 'coverage', 'karma-remap-istanbul'],
    /**
     * Simple summary (printed to the console) and JSON file which we will remap back to TypeScript.
     */
    coverageReporter: {
      dir: 'coverage',
      reporters: [
        { type: 'text-summary' },
        {
          type: 'json',
          subdir: '.',
          file: 'coverage-final.json'
        }
      ]
    },

    /**
     * Map code coverage result back to TypeScript using `karma-remap-istanbul`.
     */
    remapIstanbulReporter: {
      src: 'coverage/coverage-final.json',
      reports: {
        lcovonly: 'coverage/lcov.info',
        html: 'coverage/report'
      },
      timeoutNotCreated: 5000,
      timeoutNoMoreFiles: 5000
    },
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['PhantomJS'],
    singleRun: true,
    concurrency: Infinity,
    client: {
      captureConsole: true
    }
  })
}