SSL-Enabled Forms Show Web Page Not Available

We are having a problem with some forms working fine yesterday. The problem seems to be when using the secure link as it works fine using a not secure link. 

This is happening from multiple computers - we get the error message Web Page Not Available. Why is this happening? The secure links have been working fine all week until today. 

Thanks. 

https://secure.jotform.us/leadershipdevelopment/PDLeader

https://secure.jotform.us/leadershipdevelopment/PDOrgLeader

https://secure.jotform.us/leadershipdevelopment/PDTeamLeader

https://secure.jotform.us/leadershipdevelopment/PDPT-Camp

https://secure.jotform.us/leadershipdevelopment/PDMultiTeamLeader

PS we get this error message when we click submit. You can get to the form, but it will not submit. Thanks. 

Hi,

I've checked one of the forms and made a test submission, you'll see a test submission on this form https://secure.jotform.us/leadershipdevelopment/PDLeader. Also the forms are associated to a registered account with a username of leadershipdevelopment.  

The form seems to work fine in my end. I suspect that your internal network is blocking https:// websites of our form that is why the non-SSL or regular links work. I would recommend that you check with your Network Administrator to see where the problem is.

Do let us know if you have fixed the problem in your end. We'll wait for your response.

Thank you.