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How to Fix the ERR_BLOCKED_BY_RESPONSE Error and Stop McAfee Pop-ups in Microsoft Edge

The err_blocked_by_response error can be a frustrating roadblock when you‘re trying to access a website. This error indicates that your browser received an unexpected or unprocessable response from the web server, causing the page load to fail.

While this error can have many potential causes, a common culprit is local antivirus software. Pop-ups and overly restrictive settings from programs like McAfee can often trigger err_blocked_by_response by interfering with server communication.

According to a survey by the antivirus review site SafetyDetectives, McAfee is the 5th most popular antivirus solution globally, with over 17% of surveyed users. This widespread usage, combined with the fact that McAfee‘s WebAdvisor browser extension is known to cause issues in Edge, means a significant number of people may encounter McAfee-related err_blocked_by_response errors.

In this guide, we‘ll cover how to resolve McAfee problems step-by-step, as well as other common fixes for the err_blocked_by_response error across browsers.

But first, let‘s look more closely at what this error actually means and how to read the clues it provides.

Understanding the ERR_BLOCKED_BY_RESPONSE Error Message

Here‘s an example of what the full err_blocked_by_response error typically looks like in Microsoft Edge:

This site can‘t be reached‘s server IP address could not be found.
- Checking the connection
- Checking the proxy, firewall, and DNS configuration
- Running Network Diagnostics

The ERR_BLOCKED_BY_RESPONSE code is the key identifier that the browser has detected a problem with the server‘s response. However, the rest of the error message provides useful context clues that can point to the source of the issue.

In this case, Edge gives some initial suggestions to check your internet connection, proxy/firewall/DNS settings, or run the built-in Network Diagnostics tool. This implies the issue may be related to your own local network setup.

The inability to find the server‘s IP address could mean your DNS cache needs to be flushed. A misconfigured proxy server or VPN could be preventing Edge from establishing a clean connection. Or, as we‘ll discuss in more detail shortly, a local firewall or antivirus like McAfee may be blocking access to the site.

Of course, the err_blocked_by_response error can manifest a bit differently in other browsers. For example, in Google Chrome the error looks like this:

This site can‘t be reached
The webpage at might be temporarily down or it may have moved permanently to a new web address.

Although the specific wording differs, the ERR_BLOCKED_BY_RESPONSE code remains the same. Chrome suggests the issue could be due to the remote site being down or having changed URLs, but the local troubleshooting steps we‘ll discuss still apply.

Now that we know how to spot the err_blocked_by_response error, let‘s dive into the solutions. First up is how to deal with McAfee antivirus interference.

How to Fix McAfee Antivirus Issues that Cause ERR_BLOCKED_BY_RESPONSE

McAfee offers a variety of antivirus and security tools, but two components in particular are notorious for causing the err_blocked_by_response error in Microsoft Edge:

  1. The McAfee Firewall, which monitors and controls network traffic to block potential security threats. Overprotective firewall settings can prevent legitimate server responses from getting through.

  2. McAfee WebAdvisor, a browser extension that scans websites for malicious activity. WebAdvisor pop-ups and content blocking can break pages that would otherwise load fine.

According to McAfee‘s own support documentation, "This error occurs when WebAdvisor blocks access to websites that are possible threats, this may be a false detection."

Luckily, adjusting McAfee Firewall and disabling WebAdvisor is relatively straightforward. Here are the steps to resolve both issues:

Adjusting McAfee Firewall Settings

  1. Open your McAfee security software console (usually by double-clicking the McAfee icon in your system tray).
  2. Click the gear icon to access settings, then choose "Web and Email Protection".
  3. Select "Firewall" from the sub-menu.
  4. Find the domain of the website you‘re having trouble with, and click "Edit".
  5. Under the "Ports" tab, uncheck "Block incoming/outgoing traffic" for that domain.
  6. Click "Save" to apply the new firewall exception.

McAfee Firewall Settings
Adjust McAfee Firewall port access settings for websites that trigger err_blocked_by_response

Disabling McAfee WebAdvisor in Edge

  1. Open Edge and navigate to edge://extensions
  2. Find "McAfee WebAdvisor" in the list of extensions.
  3. If there is a "Remove" button next to WebAdvisor, click it to uninstall the extension.
  4. If WebAdvisor is grayed out and the Remove option isn‘t available, then your version of Edge (85 or newer) has already automatically disabled it.

McAfee WebAdvisor Extension
The McAfee WebAdvisor extension can often be uninstalled directly from Edge

With these McAfee-specific tweaks applied, restart Edge and try re-accessing the website that previously threw the err_blocked_by_response error. There‘s a good chance the page will load successfully now.

However, if you‘re still encountering the error, there are a variety of other common culprits to investigate beyond just McAfee. Let‘s walk through some additional universal troubleshooting steps.

General Troubleshooting for ERR_BLOCKED_BY_RESPONSE Errors

These fixes can apply no matter which browser or antivirus software you‘re using. We‘ll start with the simplest potential solution and work our way up to more advanced steps.

1. Check your internet connection

Before assuming there‘s a problem with your browser or security tools, first double-check that your internet connection itself is working properly. A weak or unstable connection can sometimes manifest as an err_blocked_by_response.

Try visiting a few other websites to see if they load successfully. If you can‘t reach any sites at all, your connection may be down. Restart your router or modem, and contact your ISP if problems persist.

2. Clear browser data

Corrupted cookies, stale cache files, or other faulty local data can prevent a website from loading as expected. Clearing this data can often resolve the err_blocked_by_response error by forcing your browser to fetch a fresh copy of the page from the server.

In Microsoft Edge:

  1. Click the three-dot "Settings and more" icon in the top-right corner.
  2. Go to Settings > Privacy, search, and services.
  3. Under "Clear browsing data", click "Choose what to clear".
  4. Select "Cookies and other site data", "Cached images and files", and any other data categories you want to remove.
  5. Click the "Clear now" button, then restart Edge.

Other browsers like Chrome and Firefox have a similar process available in their privacy settings.

3. Disable extensions and add-ons

Poorly coded or obsolete browser extensions can alter website functionality in ways that generate an err_blocked_by_response. Temporarily disable all your extensions and then re-enable them one at a time to identify any problematic ones.

In most browsers, you can manage extensions by typing chrome://extensions, edge://extensions, or about:addons into the URL bar.

Beyond just McAfee WebAdvisor, other common extensions that can cause this error include ad blockers, script blockers, VPNs, and download managers. Make sure to keep all extensions updated to minimize issues.

4. Update your browser

Using an outdated browser can lead to incompatibilities, glitches, and security vulnerabilities. The err_blocked_by_response error may appear if your browser version is too old to properly negotiate communication with the web server.

To update Edge:

  1. Click the three-dot menu icon and go to Help and feedback > About Microsoft Edge.
  2. Edge will automatically check for and install any available updates.
  3. Click "Restart" when prompted to complete the update.

Edge Browser Update
Microsoft Edge can automatically install browser updates with just a few clicks

Most other browsers will also have an "About" or "Help" page where you can initiate a manual update check.

5. Check proxy settings and flush DNS

Incorrect network configurations can interfere with your browser‘s ability to receive proper responses from websites. Two key settings to investigate are your proxy configuration and DNS cache.

A misconfigured proxy server can bottleneck traffic and even alter or block responses, triggering err_blocked_by_response failures. Make sure your system proxy settings are correct, or temporarily disable the proxy altogether.

To check proxy settings on Windows:

  1. Open the Start menu and search for "Internet Options".
  2. In the Internet Properties window, go to the "Connections" tab and click "LAN settings".
  3. Make sure "Use a proxy server for your LAN" is unchecked, then click OK.

Meanwhile, a corrupted DNS cache could be preventing your browser from contacting the correct IP address for a domain. Flushing the cache will purge any stale entries and force your system to retrieve fresh address mappings from its configured DNS servers.

To flush DNS on Windows:

  1. Right-click the Start button and select "Windows Terminal (Admin)" or "Command Prompt (Admin)".
  2. In the terminal, run the command ipconfig /flushdns.
  3. You should see a message confirming the DNS cache was successfully flushed.

Flush DNS Command
Use the ipconfig /flushdns command in an admin command prompt to clear the DNS cache

6. Temporarily disable antivirus or firewall

As we saw with the McAfee-specific steps above, antivirus software and system firewalls can often be overzealous in blocking traffic to unfamiliar sites. To determine if another security tool besides McAfee is causing the err_blocked_by_response error, temporarily disable it and test the connection again.

For third-party security suites like Avast, Kaspersky, Norton, or Bitdefender, you‘ll need to open the respective management app and locate the option to disable real-time protection or shut down the firewall component. Consult the documentation for your specific software version.

If you‘re just using the built-in Windows Security tools:

  1. Open the Start menu and search for "Windows Security".
  2. Click "Virus & threat protection".
  3. Under "Virus & threat protection settings", click "Manage settings".
  4. Toggle off the "Real-time protection" option.
  5. Back on the main Windows Security screen, click "Firewall & network protection".
  6. Click the currently active network (likely "Domain network" or "Private network").
  7. Under "Microsoft Defender Firewall", toggle the setting to "Off".

Windows Firewall Settings
The built-in Windows Firewall can be quickly toggled on and off for testing

With your antivirus and firewall disabled, try accessing the website again. If the err_blocked_by_response error has disappeared, you‘ve found the culprit and can begin further troubleshooting within that program‘s settings.

Just remember to re-enable these critical protections once you‘re done testing! Leaving them off indefinitely can expose you to malware and other threats.

In some cases, even with your antivirus and firewall disabled, you may still see err_blocked_by_response when trying to access certain sites over HTTPS (SSL/TLS). This could indicate an issue with the site‘s SSL certificate, which the browser or server may deem invalid or untrustworthy.

Unfortunately, there isn‘t much you can do on your end to bypass an untrusted certificate warning. Avoid sites that present SSL errors, as they may be insecure or even malicious. Notify the website owner of the issue, and wait for them to install a valid certificate from a trusted certificate authority.

7. Consult official support channels

If you‘ve thoroughly explored all the troubleshooting steps above and are still encountering the err_blocked_by_response error, it may be time to consult expert help through official support channels.

  • Visit your browser‘s support site or community forums to see if others are reporting the same issue and learn about resolution paths. For example, Edge users can ask for assistance at the Microsoft Edge Community.

  • Contact your antivirus software‘s customer support team for personalized troubleshooting, especially if you suspect the issue is related to a specific security feature.

  • As a last resort, reach out to the website owner and explain the error you‘re encountering. They may need to investigate and resolve an issue on their end, such as misconfigured server settings or a problematic content filter.

Remember, the err_blocked_by_response error can have numerous potential root causes across web servers, networks, browsers, and security tools. Systematic trial and error is often required to pin down the source and find a solution.

Preventing ERR_BLOCKED_BY_RESPONSE Errors in the Future

Beyond troubleshooting existing instances of the err_blocked_by_response error, there are also some proactive steps you can take to minimize the chances of encountering this and other errors going forward:

  • Keep your browser and extensions up-to-date to ensure maximum compatibility with the latest web technologies and security practices. Enable automatic updates wherever possible.

  • Be judicious about which extensions you install. Carefully vet the permissions they request and user reviews they‘ve received. Uninstall extensions you no longer actively use.

  • Regularly clear your browser cache, cookies, and other data to prevent accumulation of corrupt files that could interfere with site functionality. Most browsers have an option to automatically clear certain data types each time you close the program.

  • Fine-tune your antivirus and firewall settings to avoid overblocking. Instead of cranking up protection levels to maximum, take a balanced approach and set up exceptions for specific trusted sites as needed.

  • Maintain good overall cyber hygiene by using strong unique passwords, enabling multi-factor authentication, and following safe browsing/downloading best practices. Preventing malware infections reduces the risk of browser errors and performance issues.

Secure Browser Checklist
Follow best practices like enabling automatic updates and vetting extensions to minimize browser errors

Key Takeaways

The err_blocked_by_response error is a common issue that can be caused by everything from McAfee pop-ups to problematic proxy settings. Although this error can be discouraging, remember that most instances can be resolved with basic browser and system troubleshooting.

To quickly recap, here are the key steps to fix err_blocked_by_response in Edge and other browsers:

  1. Disable McAfee WebAdvisor and adjust Firewall settings
  2. Check your internet connection
  3. Clear browser data like cache and cookies
  4. Disable all extensions and re-enable one by one
  5. Update your browser to the latest version
  6. Verify proxy settings and flush DNS cache
  7. Temporarily disable antivirus and firewall
  8. Consult official browser and antivirus support channels

By methodically working through this checklist, you‘ll be able to resolve most err_blocked_by_response errors at their source. And by adopting proactive browser maintenance habits, you can reduce the frequency of such errors going forward.

Hopefully this in-depth guide has equipped you with the knowledge and tools needed to overcome err_blocked_by_response roadblocks and get back to uninterrupted web browsing. As our online lives become ever more essential, learning how to quickly troubleshoot browser errors is an increasingly indispensable skill for all users.