That sounds like something may be affecting your browser's ability to run Javascript; you may wish to disable any extensions or try again in an Incognito window.

Let me know if you continue to have any problems.

that addon breaks it:
https://chrome.google.com/extensions/detail/nlbjncdgjeocebhnmkbbbdekmmmcbfjd

Hm, I'm not sure about that, as I have that extension enabled and haven't come across this problem on our page.

Keep me posted if you come across anything else.

Also, if you'd rather, you could submit a Gmail issue report via our support system.