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Firefox just shows an empty "alert" popup for SSL certificate errors

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Whenever I visit a website that has an SSL certificate issue, instead of any kind of actual error page, Firefox just shows a modal "Alert" dialog box with no text.

In the attached screenshot, I visited a page I know has an SSL certificate issue. In Chrome, I get a full-page warning. But in Firefox, just the description-less "Alert" box.

I tried disabling all of my plugins before visiting the site as well and got the same result. I don't seem to have customized any of the SSL or Certificate settings in about:config either.

Does anybody have any idea how I can get something approaching normal behaviour out of Firefox for mac?

Whenever I visit a website that has an SSL certificate issue, instead of any kind of actual error page, Firefox just shows a modal "Alert" dialog box with no text. In the attached screenshot, I visited a page I know has an SSL certificate issue. In Chrome, I get a full-page warning. But in Firefox, just the description-less "Alert" box. I tried disabling all of my plugins before visiting the site as well and got the same result. I don't seem to have customized any of the SSL or Certificate settings in about:config either. Does anybody have any idea how I can get something approaching normal behaviour out of Firefox for mac?
Attached screenshots

Chosen solution

You can check xul.error_pages prefs on the about:config page and make sure they are default and not user set (bold). If necessary then reset the pref via the right-click context menu to the default value (true).

  • browser.xul.error_pages.enabled

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

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All Replies (2)

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Chosen Solution

You can check xul.error_pages prefs on the about:config page and make sure they are default and not user set (bold). If necessary then reset the pref via the right-click context menu to the default value (true).

  • browser.xul.error_pages.enabled

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

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Thank you, that was absolutely it. browser.xul.error_pages.enabled was set to "false". When I reset it back to the default of "true", I see the error page again.