Have a very similar question. Here is an example:
Creating ArcGIS Open Data Sites in 60 Minutes (or Less) | Esri Canada
The form loads without an issue, however you can see the site becomes "not secure". We've had clients tell us the form information doesn't get submitted because of their internal security settings and haven't found a way around this.
Marketo support told us to use our own CNAME in the form embed code. We were doing this before our security certificate was renewed and the forms started to disappear so I've gone back to using the original Marketo form embed code.
Any suggestions? Thanks a lot!
We've had clients tell us the form information doesn't get submitted because of their internal security settings and haven't found a way around this.
There are several mixed content warnings on the page, but the one that's related to the form has only to do with the fancy select image (the blue arrow). That isn't preventing the form from being submitted. Have you been testing this? In what browser is the mixed content blocking the form?
so I've gone back to using the original Marketo form embed code.
Thanks for the reply Sanford. This issue has been going on for us for about 6 months. Marketo couldn't figure out what it was and suggested to change the CNAME. It looks like that isn't working if the website is secure now.
We've been testing the forms internally but we have never been able to reproduce the issue consistently. We did an eblast for our webinar yesterday and received roughly about 10 individuals who said the form wasn't being submitted. I suspect it could be more and unfortunately people may not realize it. We have been saking clients to let us know what browsers they are using, and we've received an array of responses (IE, Firefox, Chrome) and most users are on Windows 7.
We are thinking about upgrading to the https landing pages and iFraming those but it is definitely not the most ideal method.
IFRAMEing has only disadvantages and if you're seeing unexpected mixed content warnings that won't fix 'em.
Are you aware that you posted the link to the plaintext version of your site? Is it possible that you're relying on redirection to the SSL version of your site, but that step not working correctly (i.e. redirecting to an statically cached older version or something along those lines)? I ask this specifically because I saw one mixed content warning because /forms.min.js attempted to load over plaintext -- but it was securely loading (from //app-ab04.marketo.com) in the source the next time I refreshed!