ReCaptcha TypeError when resending after timeout

Question

I set up a test page to work with Google reCaptcha and I get an error when the session time ends and I try to resend it. I have a demonstration of what is going on at http://kexp-web1.cac.washington.edu/GCap.html

Repro Steps

• Page loading
• Check the box next to "I'm not a robot."
• Wait for the session to end.
• See the warning, "Verification expired.
• Check the box

• Get a Javascript warning in the console "Unclear TypeError: cannot read property 'then' of null"

  

This seems to be a pretty simple mistake, but I can't find what it could be. Has anyone experienced this before?

(9/11/15) , , , , , .