Translate interface is breaking with very complex string (4 variants, 6 plurals)

[flodolo]

Found while talking with @eemeli about the new UI (Russian works, Welsh kills the browser)
https://pontoon.mozilla.org/cy/common-voice/web/locales/en/messages.ftl/?search=-%3E&string=213590

[chasingdragonflies]

Hello.
I can confirm that Pontoon interface freezes (can scroll but buttons frozen) when this string is loaded for the welsh (cy) team.

https://pontoon.mozilla.org/cy/common-voice/web/locales/en/pages/dashboard.ftl/?search=is+achievable+in+just+over&string=308148