Make sure you are not blocking content.

Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

Yes, thanks, I tried the safe mode, then I also tried the «refresh Firefox» procedure but the problem remains. I can access wikipedia.org domain with Safari, though, on both computers. I have never experienced such a weird problem. It only occurs with wikipedia.org so far, with this new version of Firefox, and nothing happens at all, no error message, nothing. The favicon of Firefox blinks once in the browser tab when I try to access wikipedia but nothing more. As if Firefox didn’t even try to load anything from wikipedia.org

Yes, thanks, I tried the safe mode, then I also tried the «refresh Firefox» procedure but the problem remains. I can access wikipedia.org domain with Safari, though, on both computers. I have never experienced such a weird problem. It only occurs with wikipedia.org so far, with this new version of Firefox, and nothing happens at all, no error message, nothing. The favicon of Firefox blinks once in the browser tab when I try to access wikipedia but nothing more. As if Firefox didn’t even try to load anything from wikipedia.org

Well, I've just tried again and now it works. On both computers. I didn't change anything. Sorry for bothering you with this. This was most unusual.

Glad to hear it works now :)

Well, I’m afraid the problem is back, after a brief interruption, and now it affects Facebook as well: sometimes I can’t acess FB at all, and sometimes I can but the images and videos won’t load. It all started with the last update. Restarting without modules of refreshing FF doesn’t change anything. Safari, Vivaldi, etc. work fine. The same problem occurs with 3 different computers under different versions of MacOS.

Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia

Hi Philippe Gindre

Wikipedia and Facebook work great for me on Mac OS 10.15 and Firefox 78.0.2 (I don't use firewalls, add-ons or other 3rd party software). Do you have Firewall, or other 3rd party software installed on your Macs?

Cheers!

...Roland

Fred: I’ve just restarted my computer in safe mode. Then I launched Firefox in normal mode then in safe mode within the computer safe mode, but the problem is still there no matter what.

Roland: no, I don’t use Firewall. I do use the built-in firewall of MacOS but it is configured to let Firefox work. I deactivated it completely temporarily nevertheless but it didn’t change anything. Today I simply can’t access at all sites like Wikipedia, Facebook, Google or Instagram with Firefox. Everything works fine with Safari though. The whole family has been experiencing the same problem since the 78.0.2 update with 4 different computers: - 2011 MacBook under MacOS 10.13.6 - late 2013 iMac under MacOS 10.14.16 - 2015 iMac under MacOS 10.14.16 (this one can access Google though) - 2018 MacBook Air under MacOS 10.14.16

Oh another 2018 MacBook Air doesn’t seem to experience these problems at all! And the main difference so far seems to be that it is under MacOS 10.15.5.

Use these links to create a new profile. Use this new profile as is. Is the problem still there?

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address bar.

Done. Unfortunately, the problem remains with a new profile used as is, without adding any module or anything. This is quite puzzling. I've used Firefox for ages and I can't recall having ever met such a strange problem.

Remove History For One Site {web link}

Open the History Manager <Control> (Mac=<Command>) <Shift> H. In the search bar, enter the name of the site. Right-click on one of the listings and select Forget About This Site. This should remove all information, including any site settings

I have just updated MacOS to 10.15.5 on the 2018 MacBook Air that was still under 10.14.16 and… everything works fine now with Firefox. I didn’t change anything to my Firefox settings of course. So there seem to be a definite connection between that problem and the OS version.

Fred: my recent history is already almost empty, it empties itself everytime I quit Firefox, so I can’t find anything about the sites I am having problems with, since I have been unable to visit them for a few days. However I went to the Preferences panel and I erased all cookies and site data for Instagram (which I can’t access either), but it doesn’t work, I still can’t access this site nor the others with the computers that are still under 10.14.16.

I suspect I could solve the problem by updating the OS on the other computers but I’m quite reluctant to do so: on one of them I still use old applications which are no longer maintained nor updated and wouldn't work at all under 10.15.5. And the other computer is too old to support newer versions of MacOS anyway.

Having Firefox synched on all my computers is something I appreciate and I’d like to be able to continue working that way, I really enjoy this browser.

I wonder whether Sync could be trying to equalize a setting that needs to be different on different MacOS versions. On the Preferences page, Sync panel, you could turn off Sync of Add-ons and Options to see whether that makes any difference. Or did you already rule that out by doing a new profile test without connecting to your Firefox Account in the new profile?

I did create a new blank profile which I didn't connect to my account, as FredMcD had suggested above, but the problem was still there. Besides, it occurs on every Mac of the family running MacOS 10.14.16 (or older), and some of them belong to my relatives, they are not synced to my Mac in any way. We use the same home network, though, obviously. Could it be related? In fact, I now have two copies of Firefox running on two different computers, one under MacOS 10.14.16 and the other under 10.15.5: they are synced through my Firefox account, and the first one doesn't work properly but the other does. This is quite puzzling. Updating MacOS was the only thing that made any difference so far. Actually it solved the problem whereas I didn't change anything to my Firefox settings. Which is odd, because I understand that most of the time, when a browser fails to connect to websites after a major update, it is because «Internet security software (including firewalls, antivirus programs, anti-spyware programs, and more) is likely preventing Firefox from connecting to the Internet». Not only this problem only affects the connection to very specific websites, not Internet as a whole, but updating the OS solves it. So this is something else. Am I the only one experiencing this?

Hi again Philippe Gindre

it definitely could be your home network/firewall/WiFi/DNS/ISP. you are the only person i know of who has these issues with macOS 10.14 that mysteriously work on 10.15. many folks use Firefox 78.0.2 on 10.14 without issue. i still think, although i may be wrong, that one of your add-ons could be blocking too.

Please let us know if you find anything.

Cheers!

...Roland

Sometimes when there is no explanation, power cycling the router (unplugging it for several seconds then plugging it in again) helps clear a mystery blockage.

Roland: I relaunched Firefox in safe mode, and I also relaunched it in standard mode with every add-on turned off «manually» so unless one of the very few add-ons I use remained active nevertheless, I suppose we can rule that out. But who knows…

jscher2000: I unplugged (litterally) the router _and_ the fiber optic box for one whole minute but when the internet connection came back the problem remained, unfortunately. I guess I could try to modify the settings of my router, but this is definitely something I am not familiar with and it has worked perfectly for years, so I’m rather reluctant to do something that might end up as a worse problem than the minor one I have. But I agree, as the problem appears very local, it might have something to do with this.

Anyway, thank you everybody for your suggestions. I’ll let you know if I ever find out what’s wrong.

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