Karma parallel cannot find any tests after starting Chrome

[ionuttibi]

• Do you want to request a feature or report a bug?

• bug report

• What is the current behavior?
  The following error is thrown:

Cannot read property 'success' of undefined
TypeError: Cannot read property 'success' of undefined
    at TestCommand.runSingleTarget (C:\Users\ionut.irimia\Documents\Diod Selfcare\selfcare-portal-frontend\node_modules\@angular\cli\models\packages\angular\cli\models\architect-command.ts:242:21)
    at process._tickCallback (internal/process/next_tick.js:68:7)

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem
  After running ng test --watch=false or ng-test or karma start karma.conf.js the browsers are starting but no test is found.

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, gitter, etc)

This is my karma.conf.js

            basePath: '..',
            frameworks: ['parallel', 'jasmine' /* or 'jasmine' */],
            plugins: [
                require('karma-parallel'),
                require('karma-jasmine'),
                require('karma-chrome-launcher'),
                require('karma-junit-reporter'),
                require('karma-spec-reporter'),
                require('karma-coverage-istanbul-reporter'),
                require('@angular-devkit/build-angular/plugins/karma')
            ],
            client: {
                clearContext: false, // leave Jasmine Spec Runner output visible in browser
                captureConsole: false
            },
            junitReporter: {
                outputDir: 'reports/junit',
                outputFile: 'unit-test.xml',
                useBrowserName: false,
                suite: '' // Will become the package name attribute in xml testsuite element
            },
            coverageIstanbulReporter: {
                reports: ['html', 'lcovonly', 'text-summary'],
                dir: 'reports/coverage',
                fixWebpackSourcePaths: true,
                skipFilesWithNoCoverage: true
            },
            reporters: ['spec'],
            port: 9876,
            colors: true,
            logLevel: config.LOG_INFO,
            autoWatch: true,
            browsers: ['Chrome_headless'],
            customLaunchers: {
                Chrome_headless: {
                    base: 'Chrome', // for windows should be Chrome
                    flags: [
                        '--headless',
                        '--no-sandbox',
                        '--disable-gpu',
                        // Without a remote debugging port, Google Chrome exits immediately.
                        '--remote-debugging-port=9222',
                        '--allow-insecure-localhost'
                    ]
                }
            },
            singleRun: true,
            client: {
                jasmine: {
                    random: false
                }
            }
        };