2013434 - YouTube Homepage Fails to Load in Firefox Across All Profiles and Modes

Status: RESOLVED INVALID

(Firefox :: Untriaged, defect)

Description

[Stephen]

Attachment: Youtube Homepage - Failure

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0

Steps to reproduce:

1. Launch Firefox normally.
2. Navigate to https://www.youtube.com/.
3. Observe that the homepage does not load (blank/partial/no JS execution).
4. Restart Firefox in Troubleshoot Mode.
5. Repeat step 2 — issue persists.
6. Create a new Firefox profile (firefox.exe -P).
7. Repeat step 2 — issue persists.
8. Fully uninstall Firefox, delete profile folders, reinstall fresh.
9. Repeat step 2 — issue persists.
10. Reboot Windows.
11. Repeat step 2 — issue persists.

Site login is not required

Actual results:

YouTube homepage fails to load entirely. The screen is blank.

Expected results:

Homepage is displayed as it is when using Chrome

Comment 1

[Stephen]

YouTube Homepage Fails to Load in Firefox Across All Profiles and Modes**

Summary:
YouTube’s homepage fails to load on this Windows 11 system in all Firefox configurations, including Troubleshoot Mode and brand‑new profiles. The issue persists across reboots and clean installs. Other browsers on the same machine work normally. This appears to be a system‑level interference affecting Firefox’s content processes.

---

Affected Versions

• Firefox Stable (latest)
• Firefox Troubleshoot Mode
• Firefox with a brand‑new profile
• Firefox after full uninstall + reinstall
• Windows 11 (fully updated)

---

Steps to Reproduce

1. Launch Firefox normally.
2. Navigate to https://www.youtube.com/.
3. Observe that the homepage does not load (blank/partial/no JS execution).
4. Restart Firefox in Troubleshoot Mode.
5. Repeat step 2 — issue persists.
6. Create a new Firefox profile (firefox.exe -P).
7. Repeat step 2 — issue persists.
8. Fully uninstall Firefox, delete profile folders, reinstall fresh.
9. Repeat step 2 — issue persists.
10. Reboot Windows.
11. Repeat step 2 — issue persists.

---

Expected Result

YouTube homepage loads normally, including JS‑driven components.

---

Actual Result

• YouTube homepage fails to load entirely.
• No extensions, themes, or custom settings involved.
• Issue persists even in Firefox’s most minimal execution environment.

---

What Has Already Been Tested

Firefox‑side elimination

• ✔ Troubleshoot Mode (extensions disabled, default settings)
• ✔ New profile with no sync
• ✔ Full reinstall
• ✔ Hardware acceleration on/off
• ✔ Clearing all site data
• ✔ No about:config modifications
• ✔ No userChrome or user.js
• ✔ No third‑party codecs or plugins
• ✔ No VPN or proxy configured in Firefox

System‑side elimination

• ✔ Reboot
• ✔ Other browsers (Chrome/Edge) load YouTube normally
• ✔ Network path is clean (same machine, same connection)
• ✔ No known malware or security alerts
• ✔ No corporate policies or GPOs

Observations

• The YouTube homepage JS bundle appears to fail silently.
• The issue affects only Firefox on this Windows installation.
• The issue persists even when Firefox is running in its most stripped‑down mode.
• This suggests a system‑level DLL, driver, or service interfering with Firefox’s content processes.

---

Additional Notes

• This is not the same issue as the known YouTube UI/ThemeRefresh bug.
• This is not an extension or filter issue (Troubleshoot Mode unaffected).
• This is not profile corruption (new profile unaffected).
• This is not a caching issue (persists across reinstalls and reboots).
• The failure mode is total JS non‑execution on the homepage, not partial UI glitches.

---

Request

Looking for guidance on:

• Whether Firefox has known conflicts with specific Windows services, overlays, or injected DLLs.
• Whether there are diagnostic flags or logging modes that can capture JS execution failure in content processes.
• Whether this aligns with any known low‑level compatibility issues.

Comment 2

[Monica Chiorean (OOO August 21st 5:30PM)]

Does the issue still reproduce for you on latest Firefox 147.0.2(20260126151322) as I am not able to reproduce this on Win11x64 (26100.7623).
Stephen, what Windows version are you using? Thank you.

Comment 3

[Stephen]

Here is the information you requested and some other that may be helpful...

Application Basics
Name Firefox
Version 147.0.2
Build ID 20260126151322
Distribution ID
Update Folder C:\ProgramData\Mozilla-1de4eec8-1241-4177-a864-e594e8d1fb38\updates\308046B0AF4A39CB
Update History
Update Channel release
User Agent Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0
OS Windows_NT 10.0 26100
Application Binary C:\Program Files\Mozilla Firefox\firefox.exe
Profile Folder C:\Users\Stephen\AppData\Roaming\Mozilla\Firefox\Profiles\rznj3hh5.Steve K
Build Configuration about:buildconfig
Memory Use about:memory
Performance about:processes
Registered Service Workers about:serviceworkers
Third-party Modules about:third-party
Launcher Process Enabled
Multiprocess Windows 2/2
Fission Windows 2/2 Enabled by default
Remote Processes 20
Enterprise Policies Active
Google Location Service Key Found
Google Safebrowsing Key Found
Mozilla Location Service Key Found
Safe Mode false
Memory Size (RAM) 63.8 GB
Disk Space Available 241 GB
Profiles about:profiles
Pointing Devices Mouse

Comment 4

[Tooru Fujisawa [:arai]]

If you mean the page with "Try searching to get started" as a result of "Fails to Load", I observe the same page also on Chrome and Safari today.
The behavior difference is observed also on our automation in bug 2007104.

So perhaps the website is performing A/B testing or something that behaves differently based on the environment.

Comment 5

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Firefox for Android::General' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 6

[Francesco Lodolo [:flod]]

Marking as INVALID for now, since this seems to be happening on YouTube's side.