How do I securely open uploaded documents?

It is not letting me open documents people have uploaded to the form. Working fine on my iphone but not my Mac desktop. Software up to date. It says connection not private??

If I understand you correctly, you're getting this error when you tried downloading the uploaded files in a Mac desktop. 

Please try using another browser just to check if it will work or not. May I also ask where are you trying to download the uploaded files? Is it from the email notifications or is it from the Submissions page in JotForm.

Also, please provide a screenshot of the issue so that we can further investigate about the issue.

We'll wait for your response. Thank you.