Firefox Community Forum

Hi, I want to use dark background color theme in the Mozilla Firefox PDF viewer, read here https://support.mozilla.org/en-US/questions/1434510 but cannot find "userContent.css". My question is where can I find this file on a Windows 7 or Windows 10 installation?

Good Morning,

I would appreciate your support if anyone can give me any idea about how to solve this issue as I lost my parameters when restarting Firefox.

Every time that I restart Firefox (115.13.0esr 64-bit), I lose most of my personalized parameters: download recording directory, toolbar customization, etc.

As an example, every time that I restart it, a new download recording directory is again customized related to a folder that I deleted 10 years ago.

I understand that I am doing something wrong or something must be wrongly in my system. Have you ever managed this situation? Could you please be so kind to provide me any guide about how to solve this issue?

Thanks in advance and kind regards, Enric

Firefox will not allow me to login to my mail a/c which I have had for more than 20 years. Because of this I cannot access a code to access my MS Outlook a/c This message shows:

'Firefox detected a potential security threat and did not continue to webmail.mercuryin.es. If you visit this site, attackers could try to steal information like your passwords, emails, or credit card details.' AND tells me that there is nothing I can do about this.

Secure connection failed and Firefox did not connect Firefox Last updated: 01/16/2024 39% of users voted this helpful

This article explains why you may see a Secure Connection Failed or a Did Not Connect: Potential Security Issue error page, and what you can do.

   If you see a Warning: Potential Security Risk Ahead error page, see What do the security warning codes mean? and How to troubleshoot security error codes on secure websites.
   To troubleshoot other error messages, see Websites don't load - troubleshoot and fix error messages. 

Table of Contents

   Secure connection cannot be established
       Secure Connection Failed
       Did Not Connect: Potential Security Issue
   Website issues
       TLS version unsupported
       HSTS required
   Security software conflict
   Incorrect system clock
   Other secure connection issues

Secure connection cannot be established

When a website that requires a secure (HTTPS) connection tries to secure communication with your computer, Firefox cross-checks this attempt to make sure that the website certificate and the connection method are actually secure. If Firefox cannot establish a secure connection, it will display a Secure Connection Failed or Did Not Connect: Potential Security Issue error page. Secure Connection Failed

A Secure Connection Failed error page will include a description of the error and a Try Again button. There is no option to add a security exception to bypass this type of error.

Fx97SecureConnectionFailed ~~~ The url gives me this can you help please its not bitdefender total security blocking it I dont think https://support.mozilla.org/en-US/kb/secure-connection-failed-firefox-did-not-connect?as=u&utm_source=inproduct

After the recent update I am no longer permitted to stream movies. How can I reverse this update, change it or will there be a patch to address this malfunction? I am not the only one that this has happened to. Every update changes my settings, I have learned to go back into settings and change back.

I installed mozilla firefox on my desktop computer 5 years ago At the time, my email address was davsue@myfairpoint.net This email no longer exists my new email address is davsue123@gmail.com I signed out of firefox I want to sign in again It sends me a confirmation email to davsue@myfairpoint.net that doesn't exist Can't retrieve the email to verify my account Now what? haven't been able to set davsue123@gmail.com as a secondary email