Sorry to hear you've had an issue downloading your campaign as a .pdf.
I went into your account and tested downloading your most recent campaign from October 9th and encountered an issue when I was using Google Chrome. Did the error message you received look like the following message?
I then tried using Chrome in Incognito Mode and the email loaded successfully and downloaded as a .pdf without issue. I also tried using Mozilla Firefox and Internet Explorer and both of them allowed the .pdf to download.
Can you please try a different browser and let us know if that works for you? If not, please let us know what browser you are using and if you changed any of the .pdf settings before downloading so we can look into the matter further for you.
It sounds like there might be a plugin in Internet Explorer that is causing the problem. You can follow the steps in this FAQ on how to troubleshoot which plugin is the cause if you would like.