Firefox Community Forum

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.

After the last Firefox Update, I can no longer log into my healthcare website. It loads login screen, enter information and it fails to redirect, returning to login screen. mymercy.net works fine with Edge and Chrome. But I have Firefox set as my default to switching is a pain! I have cleared everything.. reloaded firefox and it still does the same. Tried it with 3 different computers with the same result, so there is something about the new update that mymercy.net doesn't like. any suggestions?

Hello there.

Since last update i'm unable to browse websites like youtube, social media and all other websites with video content. Video often fails to load,the wholewebsite is not loading, freezes while played or while exiting full screen mode. All of these freezes the browser - the site cannot be refreshed, links does not work. The only way is to close the tab with the freezed page or kill the Firefox process in windows Task Manager. Refreshing, re-installing, deleting or using different profile don't work. Same with add-ons. Seems like the issue lies within the browser and it started to appear since last update.

Hi, I am using Firefox version 150.0.3 (64 bit). It says it is up to date and I'm on Windows 11and it is fully updated. I use the Colorado Peak website but can not upload documents to them or read my mail from them. I have to go to another browser to do that.

I have used Firefox as my default browser for over 20 years I don't want to give it up or use another browser even to do just a few things once in a while. Peak tech support says they have communicated with Firefox but gotten no response. Help!!

D

I’m in the market for a vpn and found out u come highly recommended. Have a few questions before I proceed with the purchase. 1. Using one account, how do i install Mozilla vpn on Windows laptop, iPhones (2), Apple watch? Each of this has their own software installation. 2. Will be traveling to the Philippines this year. Found out Mozilla does not have a vpn server servicing the country. Do you have an alternate solution? 3. If I’m traveling internationally, does your vpn software automatically switch my server closest to where I’m at or do I have to do it manually by doing a search and select function? 4. Do you offer a trial version for Mozilla vpn?

Thank u much, Tony

Hello All, I'm just into Firefox. Struggling with two untidy bars across top of screen. Need advice to reduce this to one. I have my Win11 taskbar to the left on my PC. Can't we do something to put current open site in there?

Randomly my firefix just get loggedout and when i immediately logged it in again using mozilla i cant see my bookmarks my other accounts my profiles and all my groups and other information it was like i had made a fresh account all my data is lost what to do ? PLZ help i really want my data back i have been trying to get my data. Working on it for last hour.