sitespeed.io: ERROR: TypeError: Cannot set property '_meta' of undefined

Hi,

Starting today, I am getting the following error:

[2019-02-25 15:54:52] ERROR: TypeError: Cannot set property '_meta' of undefined
    at Object.addExtrasToHAR (C:\Projects\sitespeed.io\node_modules\browsertime\lib\support\har\index.js:145:34)
    at addExtraFieldsToHar (C:\Projects\sitespeed.io\node_modules\browsertime\lib\core\engine\index.js:69:21)
    at Engine.runByScript (C:\Projects\sitespeed.io\node_modules\browsertime\lib\core\engine\index.js:167:7)

The issue can be reproduced using the following script:

module.exports = async function(context, commands) {
    await commands.navigate(
      'https://www.kolikkopelit.com'
    );
    
    try {
      await commands.wait.byXpath(`//a[@data-test-name="login-button"]`, 10);
      await commands.click.byXpath(`//a[@data-test-name="login-button"]`);

      await commands.wait.byXpath(`//*[@data-test-name="Modal-login"]`)
      await commands.addText.byXpath('testuser12_1@mailinator.com', `//input[@data-test-name="UsernameField"]`);
      await commands.addText.byXpath('passwordplaceholder', `//input[@data-test-name="PasswordField"]`);

      await commands.measure.start('login');
      await commands.click.byXpathAndWait(`//button[@data-test-name="EnabledLoginButton"]`);
      await commands.measure.stop();
    } catch (e) {
    }
  };

I am using sitespeed.io v 8.6.4 locally (Windows 10), the latest Chrome version: 72.0.3626.109 (Official Build) (64-bit). The script is run via the following command:

node bin/sitespeed.js test/login.js --multi

The log file is also attached. sitespeed.io.log

P.S.: The same script was running properly and yielding a proper report last week.