I have seen this problem on a couple of other threads but nothing I have done (that you suggested) has solved the issue. I have also checked on another site where the form was working and now it also has this error.
I have cleared the cache, the browser cache and cookies, uncombined the js files, rebuild the scripts under troubleshooting. Not in that order though 😀
It works in IE, it is an issue with a recent update in Chrome, I suspect, as you mentioned.