Why won't Jotform connect to Salesforce contacts?

I successfully integrated my Jotform form with my Salesforce contacts, however when I added a field and tried to go back into the integration to add the additional field and mapping, it just hangs on the loading screen after I select "contacts" and click next (screenshot attached). It seems to log in to Salesforce successfully and gives me the option of connecting to Leads, Accounts or Contacts, but once I select Contacts and click next it stops there. I've restarted, Jotform, logged out of Salesforce, restarted my computer, ... everything. It just hangs there. I also tried cloning the form and trying a new integration, but same problem. Any thoughts on how to fix this?

Hi,

Sometimes when you update forms, integrations and such can get broken and old version may be conflicting.  Try clearing your forms cache and then retrying the integration:

http://www.jotform.com/help/229-How-to-Clear-your-Form-Cache

Please let us know if this does not help and we will be happy to assist you further.

Thank you for using Jotform!