Download issue with converted PDF files

Hi,

I have been having issues with downloading converted PDF files. When I click on 'download', I then get the notification that the browser failed to get a secure connection. And I cannot download the file as a result. First I thought this might be a one off issue with only one file, but I encountered this problem again just now with a different file.

Is this an issue on my end, or is it a problem on the website?