Pages don't render in old browsers like IE11

Summary

While working on another report, a security researcher discovered that a change in Legal Robot's code (conversion of some code to ES6 arrow functions) caused pages not to render in older browsers like IE 11. While there was no security impact, Legal Robot asked the researcher to submit a report to track this issue and award a bounty separately. On older browsers, Legal Robot now generates a redirect to browser-update.org rather than rendering a blank page.

I discovered that a change in Legal Robot's code (conversion of some code to ES6 arrow functions) caused pages not to render in older browsers like IE 11.