When browsing the Internet or using the online app, you can sometimes come into an error message that says: “you’ve been blocked by network security.”
First, it can be misleading, but in simple words it means that your request to reach a website or app has been stopped by a security system. This can be your own network, firewall or website.
In this guide, we will explain what this error means, why this happens, and how can you fix it step by step.
What do you mean “You’ve been blocked by network security”?
This is a safety warning that tells you that your connection is blocked. Can be on the block:
- Network levels (your Wi-Fi, office firewall, school policy, or ISP), or
- Website level (website has blocked your IP address).
For reference, Microsoft also explains similar network error messages.
Common Reasons Behind the Error
Here are some of the most common causes of this error:
- Firewall or proxy restrictions: Office, schools and organizations block certain websites for safety or productivity reasons.
- Blocked IP Address: A website can block your IP if it detects suspected traffic.
- VPN or Proxy issues: Sometimes VPN services are blocked or unstable.
-
Antivirus or Security Software: Some antivirus tools may wrongly mark a website as unsafe (see Kaspersky blog for examples).
-
ISP or Router Filtering: Internet service providers or routers with parental controls may filter specific websites.
-
SSL/TLS Certificate Errors: Browsers block access if a site’s certificate is invalid (Cloudflare explains SSL/TLS).
-
Corrupted Cache or Cookies: Outdated cookies or cache files may prevent proper loading.
How to Fix “You’ve Been Blocked by Network Security”
Follow these troubleshooting stages to solve the problem:
1. Refresh and Basic Check
- Refresh the page (Ctrl + F5).
- Try another browser such as chrome, firefox or edge.
If you are at Chrome, Google Support provides detailed browser troubleshooting.
2. Clear Cache and Cookies
- Open your browser settings → Clear browsing data → remove cache files and cookies.
- Restart the browser and try again.
3. Disable VPN or Proxy
Close any VPN or proxy services temporarily.
-
Test with a direct internet connection.
4. Try a Different Network
-
If you’re on Wi-Fi, test with mobile data.
-
If it works on one but not the other, the issue is with the blocked network.
5. Flush DNS and Renew IP (Windows Users)
Open Command Prompt as Administrator and type:
Restart your browser and check again.
More details on DNS flush are available in Microsoft’s official documentation.
6. Check Antivirus or Firewall Settings
-
Temporarily disable your antivirus or firewall and test.
-
If it works, add the website to your antivirus exceptions.
7. Contact Network Administrator or ISP
- If you are on office or school Wi-Fi, contact your IT administrator.
- If your ISP is blocking it, reach their aid team.
Safety Note
- If you are on a workplace or school network, always request permission before asking to lift the restrictions.
- Avoid using illegal methods to bypass firewalls.
For security awareness, check resources from CISA (Cybersecurity & Infrastructure Security Agency).
Final Thoughts
“You’ve been blocked by network security” is a fairly common error that usually comes from network ban, VPN issues or website security policies. The good news is that simple stages such as cash cleaning, disabled VPN, flushing DNS or switching network often solve the problem. If nothing works, contacting your network administrator or ISP is the most reliable solution.
For more insights, check out this cybersecurity high school textbook.
