Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox 79.0 Closes Immediately on opening

  • 1 reply
  • 1 has this problem
  • 3 views
  • Last reply by fberlack

more options

Once Firefox 79.0 is installed on my two Windows 10 systems, it opens for a second and closes immediately. If I open Firefox from a link in my email, it opens without crashing. If I select open a new window it opens and closes immediately. If I select Open a New Private Window, it works. If I open a new tab it works. If I select Open a Link in a New Window, it works. The same problem happens why attempting to open Firefox in Safe mode.

Once Firefox 79.0 is installed on my two Windows 10 systems, it opens for a second and closes immediately. If I open Firefox from a link in my email, it opens without crashing. If I select open a new window it opens and closes immediately. If I select Open a New Private Window, it works. If I open a new tab it works. If I select Open a Link in a New Window, it works. The same problem happens why attempting to open Firefox in Safe mode.

Modified by fberlack

Chosen solution

Open the browser using a link. After, check the Home Page setting.

https://support.mozilla.org/en-US/kb/how-to-set-the-home-page

Type about:config<enter> in the address bar. If a warning screen comes up, press the I Accept the Risk button. At the top of the screen is a search bar. Type browser.startup.homepage

What is the value? Right-click and select Reset to restore its default value; about:home

Read this answer in context 👍 1

All Replies (2)

more options

Chosen Solution

Open the browser using a link. After, check the Home Page setting.

https://support.mozilla.org/en-US/kb/how-to-set-the-home-page

Type about:config<enter> in the address bar. If a warning screen comes up, press the I Accept the Risk button. At the top of the screen is a search bar. Type browser.startup.homepage

What is the value? Right-click and select Reset to restore its default value; about:home

more options

Thank you for the advice. The startup home page was set to "browser.startup.homepage https://my.yahoo.com/closeloginpopup.php." I reset it and changed it back to https://my.yahoo.com and it appears to be working correctly.