Form submit fails at OSx Sierra

Great job on the plugin!

For some reason this issue only happens to OSx Sierra version but is quite important that we fix it since it breaks the page:

Once the form is submitted it goes to a blank page that says:
{“success”:false,”error”:”There was a problem processing your submission.”

There is no validation on OSx Sierra so the form could be blank and you would still be able to submit it. I suspect this is javascript conflict related to the TinyMCE popup somehow failing on Sierra and then the JSON result being loaded as a link instead of as json request