UBlock Origin Lite: RU AdList Blocks Local Images

by Alex Johnson 50 views

Introduction

Are you experiencing issues with uBlock Origin Lite blocking images on your local development environment? Specifically, images named teaser.[any extension] might be getting blocked when the "RU AdList" is enabled. This article delves into this peculiar issue, providing a comprehensive understanding of the problem, its causes, and potential solutions. Whether you're a web developer or just someone tinkering with local files, this guide will help you navigate this specific breakage and ensure your images load correctly.

The Problem: teaser.[any extension] Images Blocked

The core issue revolves around uBlock Origin Lite, a popular and efficient ad-blocking extension, inadvertently blocking images named teaser with any file extension (e.g., .webp, .png, .jpg) when the "RU AdList" filter list is active. This behavior occurs not only on localhost environments but also when opening simple HTML files directly through the file:/// protocol. This means that even if you're just testing a webpage locally, you might encounter this unexpected breakage. The filter list in question, "RU AdList," is designed to block Russian ads and trackers, but it seems to have a side effect of blocking these specific image names.

Real-World Scenario

Imagine you're developing a website locally and have named some of your placeholder images teaser.webp and teaser.png. With uBlock Origin Lite and the "RU AdList" enabled, these images will fail to load, resulting in broken images on your webpage. This can be particularly frustrating because it's not immediately obvious that the ad blocker is the culprit. Disabling the "RU AdList" resolves the issue, confirming that it's the source of the breakage.

Prerequisites and Checks

Before diving deeper, it's essential to ensure you've ruled out other potential causes. Here’s a checklist to verify:

  • Not a YouTube, Facebook, or Twitch Issue: This issue is specific to local file loading and not related to these major platforms.
  • Valid Filter Issue: The problem stems from a filter list affecting local content, which is a valid concern.
  • Not a Duplicate: Ensure no existing issue addresses this specific teaser image blocking problem.
  • Default Filter Lists: Confirm the issue persists even with only the default filter lists enabled (excluding "RU AdList").
  • No Additional Filter Lists: Disable any non-default filter lists to isolate the problem to "RU AdList."
  • Developer Mode: Disable Developer mode in uBO Lite's settings to ensure it's not a configuration issue.
  • Filtering Mode: Verify the issue occurs in both Optimal and Complete filtering modes.
  • Browser Content Blocker/VPN: Ensure your browser's built-in content blocker, DNS blocking, or VPN isn't causing the issue.
  • Other Extensions: Disable all other extensions to confirm that uBlock Origin Lite and "RU AdList" are the sole cause.
  • uBO Lite as the Cause: Confirm that the breakage is indeed caused by uBlock Origin Lite and not a site or browser issue.
  • Up-to-date Browser: Ensure your browser is updated to the latest version.

By confirming these prerequisites, you can be confident that the "RU AdList" in uBlock Origin Lite is indeed the source of the problem.

Technical Details

The issue was reported on Chrome 142.0.7444.163 on Windows 10. The user had no other extensions enabled, further isolating the problem. The user is located in Russia, which is relevant since the "RU AdList" targets Russian ads. The configuration details provided show that the user had the default filter lists enabled, including "RU AdList," confirming that the issue arises from the default settings.

Configuration Snippet

Here's a snippet of the user's configuration:

name: uBlock Origin Lite
version: 2025.1110.1551
browser: Chrome 142 (win)
filtering:
 site: optimal
 default: optimal
permission: all
rulesets:
 easylist
 easyprivacy
 pgl
 rus-0
 ublock-badware
 ublock-filters
 urlhaus-full

The rus-0 entry corresponds to the "RU AdList," which, when disabled, resolves the issue.

Why is This Happening?

The exact reason why the "RU AdList" blocks images named teaser is unclear without examining the list's contents. It's possible that the list contains a filter rule that inadvertently matches this specific image name. Filter lists often use patterns and regular expressions to block ads, and it's conceivable that a broad pattern is catching teaser images. Another possibility is that the term "teaser" is associated with certain types of Russian ads or marketing materials, leading to its inclusion in the list. It could be a false positive, where a legitimate image name is mistakenly blocked due to its similarity to ad-related terms.

Solutions and Workarounds

If you encounter this issue, here are a few solutions and workarounds:

  1. Disable "RU AdList": The simplest solution is to disable the "RU AdList" in uBlock Origin Lite's settings. This will allow your teaser images to load correctly. However, this means you won't be protected by the specific filters in that list.

  2. Rename Images: Another workaround is to rename your images to something other than teaser. For example, you could use preview.webp or thumbnail.png. This avoids the filter rule that's blocking the teaser images.

  3. Create an Exception Rule: You can create a custom filter rule in uBlock Origin Lite to allow teaser images. This involves adding a rule that whitelists these images, preventing them from being blocked. Here's an example of a rule you could add:

    @@||localhost/teaser.*
@@||file:///*/teaser.*

    This rule tells uBlock Origin Lite to allow any resource from localhost or file:/// that starts with /teaser. Adjust the rule as needed to match your specific file paths.

  4. Report the Issue: Reporting the issue to the maintainers of the "RU AdList" can help them identify and fix the false positive. They can then update the list to prevent teaser images from being blocked.

Step-by-Step Guide to Creating an Exception Rule

To create an exception rule in uBlock Origin Lite, follow these steps:

  1. Open uBlock Origin Lite's settings by clicking the uBlock Origin Lite icon in your browser toolbar and then clicking the gear icon.

  2. Navigate to the "My filters" tab.

  3. Add the exception rule to the text area. For example:

    @@||localhost/teaser.*
@@||file:///*/teaser.*

  4. Click "Apply changes."

  5. Refresh your webpage to see if the images now load correctly.

Conclusion

The issue of uBlock Origin Lite blocking teaser images with the "RU AdList" enabled is a peculiar but solvable problem. By understanding the cause and applying the appropriate solution, you can ensure your local development workflow isn't disrupted. Whether you choose to disable the list, rename your images, or create an exception rule, you have options to resolve this breakage. Remember to report the issue to the filter list maintainers to help improve the accuracy of their filters and prevent similar issues in the future. This article has equipped you with the knowledge to tackle this specific problem and maintain a smooth web development experience.

For more information about uBlock Origin and its filter lists, you can visit the official uBlock Origin website. There, you can find comprehensive documentation, community forums, and updates about the extension.