In views/helpers/install_button.php:302: 302 sprintf(___(/*%1$s is url*/'Let me install this experimental add-on. <a href="%1$s">What\'s this?</a></label>') Why is there half a label tag inside the L10n string? Seems like a mistake to me.
This will need to be changed in the .po files too or we'll lose the L10n. ryan, let me know if I can help