The information, although useful and pretty complete, contained some factual errors, I did not want to throw anyone off, in addition, I found this thread:
Which had the same problem and a few solutions that I am working to test out right now.
Something about the configuration of our host is not allowing the PDF viewer window to resolve a https request.
Thanks for touching base, I love invoice ninja, I have configured over 60 clients who now use it and most of them white label licenses.
Hopefully I can get a proper work around for this very persistent issue.
snappdf rarely works on shared hosting. Does the hosted_ninja pdf generator work ok?
We pull the logo in from the local file system and inject it as a base64 encoded string into the design, so perhaps the system is unable to find the logo anymore? Have you tried re-uploading the logo to see if that resolves the issue?