/ _ \ \_\(_)/_/ _//"\\_ more on JOHLEM.net / \ 0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0 ============================================================ WEB BROWSER ERROR MESSAGE DEBUGGING CHEAT SHEET ============================================================ 1. ERROR: "ERR_BLOCKED_BY_CLIENT" - EXAMPLE: "POST https://example.com/api ERR_BLOCKED_BY_CLIENT" - EXPLANATION: A browser extension (like an ad blocker) is blocking the request. - RESOLUTION: Disable the extension and retry, or whitelist the site. 2. ERROR: "ERR_BLOCKED_BY_XSS_AUDITOR" - EXAMPLE: "GET https://example.com/script.js ERR_BLOCKED_BY_XSS_AUDITOR" - EXPLANATION: The request was blocked due to suspected cross-site scripting (XSS) attack. - RESOLUTION: Check your request for unsafe inputs; adjust server-side content security policy (CSP). 3. ERROR: "ERR_INSECURE_RESPONSE" - EXAMPLE: "GET https://example.com/file.pdf ERR_INSECURE_RESPONSE" - EXPLANATION: The SSL/TLS certificate of the site is invalid or expired. - RESOLUTION: Update SSL certificate or visit site with "Proceed Anyway" option if safe. 4. ERROR: "NET::ERR_CERT_COMMON_NAME_INVALID" - EXAMPLE: "GET https://example.com/index.html NET::ERR_CERT_COMMON_NAME_INVALID" - EXPLANATION: The certificate's common name does not match the requested URL. - RESOLUTION: Ensure that the server's SSL certificate matches the domain name. 5. ERROR: "ERR_CERT_AUTHORITY_INVALID" - EXAMPLE: "GET https://example.com/index.html ERR_CERT_AUTHORITY_INVALID" - EXPLANATION: The SSL certificate is self-signed or from an untrusted source. - RESOLUTION: Install the certificate in the browser or on the server properly. 6. ERROR: "ERR_SSL_VERSION_OR_CIPHER_MISMATCH" - EXAMPLE: "GET https://example.com ERR_SSL_VERSION_OR_CIPHER_MISMATCH" - EXPLANATION: The server uses an outdated SSL protocol or cipher suite. - RESOLUTION: Update server configuration to support modern SSL/TLS versions. 7. ERROR: "Download Blocked" - EXAMPLE: "Download of file.zip was blocked by the browser" - EXPLANATION: The browser deemed the file unsafe or was blocked by policy. - RESOLUTION: Check the download for viruses; whitelist the domain or download manually. 8. ERROR: "POST Blocked" - EXAMPLE: "POST https://example.com/api/v1/create Blocked" - EXPLANATION: The request was blocked by the browser's security settings or policy. - RESOLUTION: Ensure that CSRF tokens are correctly implemented; adjust Content Security Policy (CSP). 9. ERROR: "CSP Directive Blocked" - EXAMPLE: "GET https://example.com/resource.js Refused to load the script because it violates the following Content Security Policy directive: "script-src 'self'". - EXPLANATION: The request violates the Content Security Policy (CSP) set by the server. - RESOLUTION: Modify the server’s CSP to allow the required resources or correct the request. 10. ERROR: "Mixed Content Blocked" - EXAMPLE: "Mixed Content: The page at 'https://example.com' was loaded over HTTPS, but requested an insecure resource 'http://example.com/script.js'. This request has been blocked." - EXPLANATION: The site is trying to load insecure content (HTTP) on a secure page (HTTPS). - RESOLUTION: Update all content to be served over HTTPS. 11. ERROR: "Cross-Origin Request Blocked" - EXAMPLE: "Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://api.example.com/data. (Reason: CORS header 'Access-Control-Allow-Origin' missing)." - EXPLANATION: The request was blocked due to missing or incorrect CORS headers. - RESOLUTION: Configure the server to include the appropriate CORS headers. 12. ERROR: "ERR_HTTP2_PROTOCOL_ERROR" - EXAMPLE: "GET https://example.com/data ERR_HTTP2_PROTOCOL_ERROR" - EXPLANATION: A generic HTTP/2 protocol error occurred, often due to a server-side misconfiguration. - RESOLUTION: Review server logs, check for HTTP/2 compliance, and ensure the server software is up-to-date. 13. ERROR: "ERR_PROXY_CONNECTION_FAILED" - EXAMPLE: "GET https://example.com ERR_PROXY_CONNECTION_FAILED" - EXPLANATION: The browser cannot connect to the configured proxy server. - RESOLUTION: Verify proxy settings in the browser or network configuration. 14. ERROR: "ERR_TUNNEL_CONNECTION_FAILED" - EXAMPLE: "GET https://example.com ERR_TUNNEL_CONNECTION_FAILED" - EXPLANATION: A failure occurred when attempting to establish a tunnel (usually over HTTPS) through a proxy. - RESOLUTION: Check proxy settings and firewall rules that may be blocking the connection. 15. ERROR: "ERR_CONNECTION_RESET" - EXAMPLE: "GET https://example.com ERR_CONNECTION_RESET" - EXPLANATION: The connection was unexpectedly closed by the server. - RESOLUTION: Ensure server stability, check network hardware, and firewall rules. 16. ERROR: "ERR_QUIC_PROTOCOL_ERROR" - EXAMPLE: "GET https://example.com ERR_QUIC_PROTOCOL_ERROR" - EXPLANATION: An issue occurred with the QUIC protocol (used by Google services). - RESOLUTION: Disable QUIC in browser settings or review server-side QUIC implementation. 17. ERROR: "ERR_NAME_NOT_RESOLVED" - EXAMPLE: "GET https://example.com ERR_NAME_NOT_RESOLVED" - EXPLANATION: The domain name cannot be resolved to an IP address (DNS failure). - RESOLUTION: Check DNS settings, and ensure the domain is correctly configured and available. 18. ERROR: "ERR_CONNECTION_TIMED_OUT" - EXAMPLE: "GET https://example.com ERR_CONNECTION_TIMED_OUT" - EXPLANATION: The connection attempt to the server timed out due to no response. - RESOLUTION: Verify server availability, network latency, and firewall settings. 19. ERROR: "NET::ERR_CERT_REVOKED" - EXAMPLE: "GET https://example.com NET::ERR_CERT_REVOKED" - EXPLANATION: The SSL certificate for the site has been revoked by the issuing authority. - RESOLUTION: Obtain and install a new SSL certificate for the domain. 20. ERROR: "Page Blocked by Company Policy" - EXAMPLE: "Access to https://example.com has been blocked by your organization's policy." - EXPLANATION: The site is restricted by enterprise security policies. - RESOLUTION: Contact IT or network administrators to request access if needed. 21. ERROR: "Script Blocked by Enterprise Security" - EXAMPLE: "Script from https://example.com/script.js was blocked by enterprise security settings." - EXPLANATION: Enterprise security solutions like firewalls or endpoint protection are blocking the script. - RESOLUTION: Whitelist the script in security software or modify security settings accordingly. ============================================================ DEBUGGING TIPS FOR EDGE, CHROME, AND FIREFOX ============================================================ - **Use Developer Tools (F12)**: Inspect the console and network tabs for detailed error logs. - **Clear Cache**: Issues may arise from outdated files. Clear browser cache and cookies. - **Disable Extensions**: Extensions can interfere with requests. Test with all extensions disabled. - **Check Security Settings**: Ensure browser security settings are not overly restrictive. - **Review Server Logs**: Server-side logs can provide additional context for request failures. - **Update Browser**: Ensure the browser is up-to-date to avoid compatibility issues. - **Use an HTTP Debugger**: Tools like Fiddler or Wireshark can help trace the exact request/response flow. - **Consult IT/Network Admins**: In enterprise environments, policies and firewall settings may require administrative changes. ============================================================