Forum der Gemeinschaft Firefox

When using other browsers I can highlight an article or portion of an article and then right click and have access to the "Print" function or "Copy" function. I've tried that several times with Mozilla but don't get that option upon right clicking my mouse. How do I print or copy an article?

I'm reposting a question already opened here because a moderator suggested to do so. Actually I though I was posting to the international forum from the URL...

I was trying to access a local HTTPS website of an embedded device (a Siemens S7-1500 PLC) that is using a self-signed certificate, but was unable to go on (attached image #1, in Italian language) due to the the SEC_ERROR_REUSED_ISSUER_AND_SERIAL error. I've browsed a similar PLC webserver in the past, so the fact that the device exposes a similar certificate serial number is not so strange for me, considering also it's self-signed.

The problem is that I cannot follow the instructions of the Mozilla knowledgebase here because I'm not able to identify the correct certificate of the website!

In the attached image #2 you can see that the connection is detected as not encrypted, I suppose because only the form part of the HTML that is posting the data using HTTPS while the rest is using HTTP, but I'm not sure. If I click on the padlock icon (attached image #3) the info about the current certificate is not displayed.

Then I went into Tools > Options and searched for "certificates"; as you can see in the attached images #4 and #5, neither in the Servers tab nor in the Authorities tab I can find any item that is related to 192.168.10.2 (the webserver IP address) or Siemens (the embedded device manufacturer). But unfortunately the error persist! Initially there was a 192.168.10.2:443 line in the Servers tab and I removed it and restarted Firefox, but it didn't solve, so at the moment the situation is the one depicted by the attachments.

I had to use Microsoft Edge to access the website, but I would like to solve this issue and use Firefox instead. Is there anything else I can do to bypass the error? Why doesn't the error page provide a way to correctly identify the wrong certificate using its fingerprint and/or name? Or, maybe, is there a way to disable this check for local IP addresses or for items in a whitelist?

Thanks for your help.

• • Background:**

I'm a senior software engineer running Firefox Developer Edition on a Linux machine with 8GB RAM. I have Fission architecture (site isolation) enabled, which I understand is now the default since Firefox 95+.

• • The problem:**

When I open 20 or more tabs across different domains, Firefox's memory consumption scales dramatically — often reaching 4–6GB of RAM for what should be lightweight browsing sessions. This is significantly higher than what I observed before Fission was enabled.

• • What I've already tried:**

- Disabled hardware acceleration → no significant improvement - Set browser.tabs.unloadOnLowMemory to true → partial relief

 but tabs reload constantly, disrupting workflow

- Reduced content.notify.interval → marginal improvement - Tested with all extensions disabled (safe mode) → RAM usage

 still high, confirming it's not extension-related

- Checked about:memory → large number of separate

 "Web Content" processes, one per origin as expected with Fission

• • What I'm trying to understand:**

1. Is there a way to set a maximum process count cap for Fission

  without fully disabling site isolation? I found 
  dom.ipc.processCount but changing it doesn't seem to affect 
  Fission's per-origin process spawning behavior.

2. Is browser.tabs.min-warm-process-count a relevant setting here

  and what is the safe range to modify it?

3. Does Firefox have a built-in memory pressure threshold where

  it automatically consolidates processes — similar to Chrome's 
  memory saver — and if so, which about:config keys control it?

• • Environment:**

- Firefox Developer Edition 151.0b10 - OS: Ubuntu 24.04 LTS - RAM: 8GB - Fission enabled: confirmed via about:support - Extensions: disabled for testing

On last Firefox update my Password manager was blanked out. I had no username/passwords in my Password Manager although I had previously had over 100. I managed to recover it by logging in to my Mozilla account but now have access to over 7000 of other peoples usernames and passwords on my password manager. You seem to have a major data breech or is this a quirk I don't understand? These other names/passwords show up when I try to log into certain sites, such as Schwab for example, and I have to pick mine out of a host of others to fill in the login info. What is going on?

Gentlemen, isn't your browser using a lot of RAM? I've been freaking out about it in recent years. That's only with 25 tabs open!! Despite the fact that the system was installed just a day ago, without any tweaks!!!

seems that after Firefox 150.0.3 (20260511200624). I cant access locally deployed servers that are not secure. the Firefox forces https when hitting http://localhost. I've tried to disable the HTTPS setting altogether. Even in developer mode it still overwrites http to https.

i had ask the servicefrom ugreen nas why they didnt provide a firefox app in nas store , they said which i am using a global version ，not a local version of nas , and firefox limited provide to china local user , is that real ?

Hi folks, my primary password suddenly stopped working when trying to look at saved passwords today. I've changed it to a new one, needing to type in the old password to do so. That worked, which verifies I had the correct password to begin with.

I then updated the browser to the latest version. When I type in the new password on startup of Firefox it works fine to reopen all the old tabs.

However when I go to look at any of the saved website passwords, the problem reoccurs again. I type in the new password but the box shakes, refusing it.

How can it be that the primary password lets me in fine when starting up Firefox, yet I get the shaking login box when I try to look at any saved website passwords? Surely if the primary password works for one it should work for the other?

Thank you, Shane