What Firefox version are you running? And which website are you having this trouble on?

Some more info that can help debug the problem: 1. What ETP (Enhanced Tracking Protection) mode are you using - Standard or Strict? You can check in Preferences -> Privacy and Security. 2. Are you using Regular window or Private window? 3. Check and report the values of these prefs in about:config

  network.cookie.cookieBehavior.optInPartitioning
  network.cookie.CHIPS.enabled

4. In the shield panel in the Firefox toolbar, do you see any trackers listed as blocked?

wow....I had an answer typed up, checked the shield and it all disappeared new firefox 13.0.1 Standard 3. I have no idea what this means or how to check it 4. I have the shield turned off.....actually didnt realize what it was, I'm ashamed to say. I've listed Paypal in Accept list for collecting cookies. I've cleared the cache numerous times.

Can you tell me how to be notified with your response? I just stumbled on this answer poking around with the update to Firefox. Even though I have posted before, I don't think it was Mozilla Connect because it registered me as new. So how did you see my question?

Safari works fine with Paypal.

I just tried to make a donation with Paypal again but turned off the shield for the page. Didnt make a difference

Can you see if you have any addons installed? Some addons can block scripts that can break websites like Paypal. Some addons I've seen cause issues are Disconnect, Ghostery, ClearURLs, Malwarebytes Browser Guard and DuckDuckGo Privacy Essentials. Even your adblocking addons could be causing this. Some of those are uBlock Origin, AdBlock Plus, Adblocker Ultimate and AdGuard.

Read this article to view your addons and disable any of the ones mentioned above: Disable or remove Add-ons

If you don't have those addons, let us know what you do have. You can also test disabling all of the addons then testing Paypal again. If it works, you will know one of the addons was at fault.