Error with the uBlock Origin extension when navigating forward and backward in Firefox.

[Chocolate-99]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

I’m having a problem with the uBO extension: when I use the back or forward arrows, it stops blocking ads, trackers, and other elements. There is an error affecting some websites—it works on some but not others. I hope there is a solution and that it gets fixed so it works like it used to.

firefox_gAcALnHYmu.mp4

A specific URL where the issue occurs.

https://ww3.gnulahd.nu/ver/linternas/

Steps to Reproduce

The issue occurs when using the forward and back arrows.

Expected behavior

It needs to function normally, just as it did before.

Troubleshooting information

uBlock Origin: 1.75.0
Firefox: 156
filterset (summary):
 network: 416375
 cosmetic: 297501
 scriptlet: 74924
 html: 4129
listset (total-discarded, last-updated):
 added:
  https://raw.githubusercontent.com/gijsdev/ublock-hide-yt-shorts/master/list.txt: 16-0, 14d.2h.57m
  ublock-experimental: 19-0, 1h.21m Δ
  adguard-generic: 102203-5890, 4d.2h.53m
  adguard-mobile: 12841-100, 4d.2h.53m
  adguard-spyware-url: 2642-125, 4d.2h.53m
  block-lan: 91-0, 14d.2h.59m
  curben-phishing: 179297-50, 1h.21m
  adguard-cookies: 40480-117, 4d.2h.53m
  ublock-cookies-adguard: 5845-82, 4d.2h.53m
  fanboy-cookiemonster: 47897-4019, 4d.2h.53m
  ublock-cookies-easylist: 5845-5845, 4d.2h.53m
  adguard-social: 26931-45, 4d.2h.53m
  [13 lists not shown]: [too many]
 default:
  user-filters: 2-0, never
  ublock-filters: 54400-74, 1h.21m Δ
  ublock-badware: 10127-17, 1h.21m Δ
  ublock-privacy: 4141-2, 1h.21m Δ
  ublock-unbreak: 2897-1, 1h.21m Δ
  ublock-quick-fixes: 543-13, 1h.21m Δ
  easylist: 88762-1369, 1h.21m Δ
  easyprivacy: 56602-148, 1h.21m Δ
  urlhaus-1: 46490-6, 1h.21m
  plowe-0: 3560-1474, 1d.1h.25m
  spa-0: 3813-37, 1h.21m
  spa-1: 7254-302, 4d.2h.53m
filterset (user): [array of 2 redacted]
userSettings:
 advancedUserEnabled: true
hiddenSettings:
 userResourcesLocation: [redacted]
supportStats:
 allReadyAfter: 1611 ms (selfie)
 maxAssetCacheWait: 924 ms
 cacheBackend: indexedDB

[Chocolate-99]

This same problem is happening in Firefox for Android with uBlock Origin and its filters enabled.

[gorhill]

Your navigation using the backward/forward arrows invokes the back/forward cache, there are no network requests made that need to be blocked. Please use the logger to verify that network requests which are meant to be blocked are not in fact blocked before opening such issues.

[Chocolate-99]

This is what the uBO logger shows me; sorry, I'm not very tech-savvy with this sort of thing. I just wanted to report this issue so the uBO team could fix it. I also want to mention something else I experienced with the Brave browser: it has the same problem with "Brave Shields." Since Brave Shields uses the same filters as uBlock Origin, it suffers from the same issue I reported. brave/brave-browser#54032

[gothic-bum]

The logger screenshot that you provided shows that filtering is indeed occurring.

[Chocolate-99]

So, how can this problem be solved? The developers would need to address the extent of this issue, because it wasn't like this before; it used to work perfectly, but now it doesn't.

[gothic-bum]

There isn't a problem to solve.

uBO is functioning properly based on the logger screenshot you provided.

The counter on the uBO icon specifically displays the number of blocked network requests, and as gorhill previously stated:

Your navigation using the backward/forward arrows invokes the back/forward cache, there are no network requests made that need to be blocked.

[Chocolate-99]

I have a question—I'm not a tech expert. Regarding the uBlock Origin (uBO) icon counter: when it shows zero, is it still blocking ads, trackers, and so on by default?

Also, regarding Brave Shields—which uses the same filters as uBO: when it shows zero, does it also block ads and trackers by default? I just want to know these two things so I can understand it a bit better.

[gothic-bum]

I have a question—I'm not a tech expert. Regarding the uBlock Origin (uBO) icon counter: when it shows zero, is it still blocking ads, trackers, and so on by default?

When the counter on the uBO icon shows zero it means that no network requests were blocked. Network requests aren't made for resources that are cached by your browser.

Note that the counter on the uBO icon does not include elements that are hidden by cosmetic filters or JS scriptlets which are injected into the page. Again, it only displays the number of blocked network requests.

You can use the logger to determine what is being actually filtered by uBO, and from which source(s) the filtering is coming from.

---

Also, regarding Brave Shields—which uses the same filters as uBO: when it shows zero, does it also block ads and trackers by default? I just want to know these two things so I can understand it a bit better.

That is out-of-scope for this repo, ask in a Brave support forum.

[Chocolate-99]

Okay, thanks for the explanation. From my point of view, when the uBlock counter shows zero, it means there's an error; they really ought to fix that glitch. I hope @gorhill steps up and resolves this serious issue. Thanks again for the explanation.

[gothic-bum]

Again, it isn't a "glich" or an issue with uBO. It is working as designed to specifically show the number of blocked network requests.

The issue is your lack of understanding of what the counter actually represents, and your incorrect assumption that a zero count indicates an error.

[stephenhawk8054]

If you think ads or trackers requests are leaking due to this, use browser devtools and see which of those requests are connecting.

Again, as we said, using back and forward navigation just triggers browser's cache to display the site. There are no connections there, hence uBO is displaying correctly.