Show us something. What happens on this site? see screenshot https://www.irs.gov/downloads/irs-pdf

What happens when you try to access a PDF -- does Firefox suggest downloading it instead of showing it in a tab in the built-in PDF viewer? Or Firefox does nothing? Or the new tab is blank?

For reference on setting Firefox's PDF handling preference: Choose your preferred PDF viewer in Firefox.

I have a similar issue

If it's from a secure site I will click on the PDF link to download a bank statement, for example, and it will "download" a blank document.

The Link isn't a direct link either, I cannot just "Right Click Download" the item, it's a secure link on the site that sends me to another location, likely randomized for security purposes.

But Firefox reads or downloads the file name and type, but the content is missing. Leading to a file of 0kb.

Adobe Reader cannot read the file because, again, it's blank.

Changing the application that opens / reads the PDF doesn't change this behavior.

This has been on going for some time, and while I have been switching to Chrome to download these statements... I don't want to do that. I want to use Firefox.

If it's from a secure site I will click on the PDF link to download a bank statement, for example, and it will "download" a blank document. The Link isn't a direct link either, I cannot just "Right Click Download" the item, it's a secure link on the site that sends me to another location, likely randomized for security purposes.

I assume the PDF never displays in a tab.

One possible reason for this problem is failure of the second server to detect that you are authorized to access the file. And that might be due to Firefox's "Total Cookie Protection" feature, which limits how sites can use "third party" or "cross-site" cookies, meaning cookies from different websites than the one you see in the address bar. When sites pass you back and forth between different servers, problems can arise.

Try making exceptions to this feature on the first page, where you click the link, and if possible on the second server, if any page opens there. To do that, click the shield icon at the left end of the address bar (next to the lock). On the drop-down, click the blue slider switch to disable protection.

More info in the following articles:

• Introducing Total Cookie Protection in Standard Mode
• Total Cookie Protection and website breakage FAQ

Any difference?