I-Firefox Community Forum

I'd like to ask about Firefox's behavior and settings. I'm using Firefox with vertical tabs (using an add-on), but it seems to be behaving strangely. The things that have changed since before are: 1. Open from pinned tab 2. Now opens in a new tab → Previously it opened in the same tab 3. Clicking on a newly opened tab opens a new tab again → Previously it would open pinned tabs/same tabs → in a new tab It has changed. I haven't changed any of my Firefox settings. Windows 11 Home 23H2 Firefox version 139.0.4 (64-bit).

When I go to YouTube to watch videos the Vid's always stop after a short time. The refresh page and back buttons do not work and neither does the ability to click on any links on the page. I have to close the tab and start again. The issues still occur on new tabs. Eventually I have to close FireFox altogether but when I try to open FireFox again it does not work or takes a few minutes and sometimes the message Firefox is still running. At times I have had the sound of the videos, when they do play, from YouTube still playing even when the browser is closed.

I chose passwords and sign in, but there's more. You are already aware of the Facebook issues but there are others issues with this and I personally don't have time to tell you how to do your job. I have to keep up my production to keep my job. Your browser really cost me labor time. So, I would like to know do you recommend going back to a previous version until you fix this mess? OR... what ohter browser would you recommend as your replacement?

I appreciate your time, and I look forward to your answer.

Thank you R

Error message: the bookmarks and history system will no be functional because one of Firefox's files is in use by another application. Some security software can cause this problem.

I tried following the directions in "learn more" but to no avail. Please help this senior citizen get his bookmarks back! Thank you.

https://e-nidhi-v2.bihar.gov.in/rms-portal-ui/rms_ReceiptCreation?encData=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&merchant_code=REGISDEPT

Peer’s Certificate issuer is not recognized.

HTTP Strict Transport Security: false HTTP Public Key Pinning: false

Certificate chain:

MIIHITCCBQmgAwIBAgIPe9HbuzjrJVIH/vX63YhtMA0GCSqGSIb3DQEBDAUAMFMx CzAJBgNVBAYTAklOMSUwIwYDVQQKDBxlTXVkaHJhIFRlY2hub2xvZ2llcyBMaW1p dGVkMR0wGwYDVQQDDBRFTSBEViBUTFMgQ0EgLSBHMkEtMTAeFw0yNTEwMDMxMTMw MzhaFw0yNjEwMjgxMTMwMzhaMBkxFzAVBgNVBAMMDiouYmloYXIuZ292LmluMIIB IjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuGmKn0XZAyekVrpXOZbaqwZq db2M18Z26Xv5oWljfLD8eBFQxjQMGtL5C/+lLarXCvr2F2CRA7Xp7Fyj7VLFeAmJ j2z6QMucxpHa13bRkBXy/lqurC4J4stfsMhtL5RWsztSsRtnAoPwbopgWvw/BDnW 0bh7E8pOUY1ePz577iRDj3WGVUryTa33HiAvEJdPmUB4XiiYBMIZhyl6x7iS9NQj gOg5quPNI2YI1NwrD7vB20/6t63muTkVCD4LGdb0+yotQn7DQ0MyA5oATifHCWpD fS1N5+7jSaTqPgPpz+8KV8gpHieO2a1Omz3icjJk8uT6O9/mJYAKK2wx2WgDpQID AQABo4IDKjCCAyYwHwYDVR0jBBgwFoAUE1weGJYNA3nLBAmvj50U0C6223AwHQYD VR0OBBYEFJuz/Oeksa16P2P29qOoAckGUTaVMBMGA1UdJQQMMAoGCCsGAQUFBwMB ME8GA1UdIARIMEYwOgYMKwYBBAGDjiEBAAEBMCowKAYIKwYBBQUHAgEWHGh0dHA6 Ly9yZXBvc2l0b3J5LmVtc2lnbi5jb20wCAYGZ4EMAQIBMHgGCCsGAQUFBwEBBGww ajAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AtYS5lbXNpZ24uY29tMEIGCCsGAQUF BzAChjZodHRwOi8vcmVwb3NpdG9yeS5lbXNpZ24uY29tL2NlcnRzL0VNRFZUTFND QUcyQTFFRS5wN2MwOAYDVR0fBDEwLzAtoCugKYYnaHR0cDovL2NybC5lbXNpZ24u Y29tP0VNRFZUTFNDQUcyQTEuY3JsMCcGA1UdEQQgMB6CDGJpaGFyLmdvdi5pboIO Ki5iaWhhci5nb3YuaW4wDgYDVR0PAQH/BAQDAgWgMAwGA1UdEwEB/wQCMAAwggGB BgorBgEEAdZ5AgQCBIIBcQSCAW0BawB3ANgJVTuUT3r/yBYZb5RPhauw+Pxeh1Um DxXRLnK7RUsUAAABmanWpcUAAAQDAEgwRgIhAO10xa+Gco+QGukLk1vRoEl88r2x eIJNe/hkH2AL7b6dAiEA/gp3Cw0Lr1QMDsZE4hc+fuDfJ8atDBdUMpZAeZkNevEA dwDLOPcViXyEoURfW8Hd+8lu8ppZzUcKaQWFsMsUwxRY5wAAAZmp1qtrAAAEAwBI MEYCIQDwG25Z2OCbiH8wVer36fVvfeJJiAG4i3LLSdNi9IfiEQIhAK2VZFgXFWd+ FTv3uazObtb5uicEUBVVwTpk/9cLoOMzAHcArKswcGzr7IQx9BPS9JFfER5CJEOx 8qaMTzwrO6ceAsMAAAGZqda2UgAABAMASDBGAiEA8AIF2gnkDl9r6HsYTATYbvzQ g/lq5i8B/MqENBs5dkwCIQC05B2VIIKRq185Z9HUiriglD4OeBz+X9ixCZQOseD7 yDANBgkqhkiG9w0BAQwFAAOCAgEABY9VYC2YHUNHebWF54NWm7dp9p86ZNyZyl7m bXNcbmUazeb5L/5qRjgacVdzIK3/BHc50eEtgFfhCjmwrx4vJG1fqRTFrPgPjSfx Sbx1X4tPZE5aMwtsoL+qOZAWARwNQcU2H6q5zAUj5yMNGVwEyIsuaerJBayImYGZ DDv9XPnMqjrwTMAF3sjfnLVEbVf4JrgJzb5cDrOY1BfGFPj3j5gw5cOljjqnGuKi kOdtxtsI2wLxjnHSYRLDl/NiZxaIhgJiCO6alJ44uRv9e2XeYJO4goagiK7lvISb jfqmU1pSEPlivfhKYDWNJ5d07TQjIj24YJnwboko23JneyjnOhqUXyihLp/9LbVI 6ShhvMEyBn2cWd++xnmXcMSdHXmABE3xs+2f7wiFnEIGFxoXiljCnRQ72S18gU9U XjxN1aaeZEC2n1XJh2yFlfXgcdDe2wHQIAnyNIzKpfAIMniDuZbxZS9NmeO6f2wR 4sVucfIQ2GZz6opgp2NGUfv95Yezc6q2emXFsjlySv8ycqiCAFUNwd8AF2BxN9dq FOLn5Nb7faorNG7P+l+DUoK21lNLcuyy0MXhX5Wte3W4WtJstBWAQG6Vm3z9aj7P j8HrnpEJHoEsIpQCn8tDIut69YEj8WC1PjD/ZWQBV6PKdvb7bSlMtuPhwBtJwIXK CI8wXto=

With vertical tabs and expand on hover, clicking on the X box rarely closes the tab. Sometimes I have success if the pointer is on the left or right line of the box. Not having luck on the center of the box. Has been true for several weeks. With hover off, clicking the X works fine. I am running Windows 11.

Pop-up blocker Inable please because of some of site setting pop-up blocked. Please open pop-up option in firefox browser site setting allowed.link text

I’ve been troubleshooting a strange networking issue in Firefox that I haven’t been able to pin down, and it seems to be specific to Firefox’s network stack rather than my system or connection.

On several high-traffic sites that sit behind Cloudflare (Discord, Shopify storefronts, some SaaS dashboards), Firefox occasionally stalls during page load. The request shows up in the Network panel as pending for several seconds before finally completing. Sometimes the page partially renders and then hangs until the stalled requests finish.

A few things that make this confusing:

• The same sites load instantly in Chromium-based browsers on the same machine and network • The issue persists even in Firefox Troubleshoot Mode with extensions disabled • DNS over HTTPS on/off does not appear to change behavior • Packet captures show the TCP connection is established quickly, but some HTTP/2 streams appear to wait before data begins flowing • If I force HTTP/1.1 using a proxy for testing, the issue disappears

System details:

OS: Windows 11 Firefox: latest stable release Connection: fiber, low latency, no packet loss locally No system proxy configured

Things I’ve already tried:

• Clearing cache and site data • New Firefox profile • Disabling hardware acceleration • Testing with network.http.http2.enabled toggled • Comparing HAR logs with Chromium

One thing I noticed in the Firefox networking logs is that multiplexed streams sometimes wait behind earlier streams longer than expected, almost like there’s some internal prioritization or queue behavior happening. I’m wondering whether this could be related to HTTP/2 prioritization logic, connection coalescing, or how Firefox handles Cloudflare edge endpoints.

Has anyone seen similar behavior or knows whether there are any advanced networking prefs in about:config worth experimenting with (connection limits, HTTP/2 concurrency, etc.)?

Curious if this might be a known quirk with certain CDNs or just something unique to my environment.

Just as the summary says, Used to have an icon that I put under the "hamburger" menu on the bookmarks toolbar that opened the bookmarks menu. Can't remember how I got it there. Can someone help me get it back.

Since a recent update, whenever I try to go to ufc.om, Firefox shows me the error in the attached image. It used to display ufc.com without issues before the update [ don't remember which update ].

Other browsers [ Chrome and Edge ] display ufc.com without issues.

An error occurred during a connection to netfoundation.itslearning.com. PR_CONNECT_RESET_ERROR

Error code: PR_CONNECT_RESET_ERROR

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem.