If it is a public website, could you post it here so we can have a look at it?

Public site (brokeage house) but the information in the PDF is confidential.

Was told by the website that "we recommend using the most recent versions of either Google Chrome or Microsoft Edge. Other browsers, such as Safari or Firefox, are not compatible and will cause viewing issues. Our best suggestion at this time would be to check and confirm that you are using the most recent browser version." I prefer Firefox, so does anyone have a suggested fix for Firefox?

Sounds like game over to me. If you're not going to give use site, how can we help?!

Okay, the site is www.traderydex.com and I was trying to download my investment statement. Google Chrome took less than2 seconds to do the task, Firefox bombed.

What happens if you try to open the PDF file in a new tab or do you need to download the file ?

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block content (Adblock Plus, NoScript, DuckDuckGo PE, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block content.

• make sure your extensions and filters are updated to the latest version
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Firefox shows a purple shield instead of a gray shield at the left end of the location/address bar in case Enhanced Tracking Protection is blocking content.

• click the shield icon for more detail and possibly disable the protection

You can check the Web Console for relevant-looking messages about blocked content.

• https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop
• https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection
• https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track

You can try these steps in case of issues with webpages:

You can reload webpage(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Settings).

"Remove the Cookies" for websites that cause problems:

• Settings -> Privacy & Security
  Cookies and Site Data: "Manage Data"

"Clear the Cache":

• Settings -> Privacy & Security
  Cookies and Site Data -> Clear Data -> [X] Cached Web Content -> Clear

• https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox
• https://support.mozilla.org/en-US/kb/how-clear-firefox-cache

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

• https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop
• https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection
• https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track

Searching their site for pdfs, I can open it with no issue. Just as a test, what happens when you click on the 1st link in the screenshot? see screenshot --> https://paste.opensuse.org/35955308 https://www.google.com/search?client=firefox-b-1-d&q=site%3Atraderydex.com+*.pdf

Can confirm, can open both pdf files with no issues on 100.0.2 (although the site wouldn't see the 2)

Interesting... Not sure what to tell you about your private pdf because we cannot see anything. Post a screenshot of your issue with the private pdf so we can get some idea and just cover personal info.

Using the Microsoft Snipping Tool, this is what I get when I click on the PDF icon on Guggenheim's site: my secure web page. The response makes no sense as the time was less than 5 seconds.

I am using Firefox 101.0 and it says that it is up to date.