Google reCAPTCHA v3 Troubleshooting Guide

If you receive a Google reCAPTCHA-related error while signing in, the issue may be caused by browser extensions, DNS filtering, firewall/security software, SSL inspection, VPN/proxy usage, or browser privacy settings.

Please follow the steps below based on your operating system.

Windows Troubleshooting

1. Check Your reCAPTCHA Score

Open:

https://antcpt.com/score_detector/

Wait for the test to complete and take a screenshot of the result.

Please provide the screenshot to Support Team.


2. Test in Private Browsing Mode

Google Chrome

  1. Open Chrome.
  2. Click the three dots in the upper-right corner.
  3. Select New Incognito window.
  4. Open the affected login page.
  5. Test the login again.

Shortcut:

Ctrl + Shift + N

Microsoft Edge

  1. Open Edge.
  2. Click the three dots in the upper-right corner.
  3. Select New InPrivate window.
  4. Open the affected login page.
  5. Test again.

Shortcut:

Ctrl + Shift + N

Mozilla Firefox

  1. Open Firefox.
  2. Click the three-line menu.
  3. Select New private window.
  4. Test the login again.

Shortcut:

Ctrl + Shift + P


3. Disable Browser Extensions Temporarily

Chrome

Enter:

chrome://extensions

Disable all extensions temporarily and restart Chrome.

Edge

Enter:

edge://extensions

Disable all extensions temporarily and restart Edge.

Firefox

Enter:

about:addons

Select Extensions and disable the installed extensions temporarily.

Pay special attention to:

  • Ad blockers
  • Privacy extensions
  • Password managers
  • Security extensions
  • Script blockers
  • Antivirus browser extensions

If the issue is resolved, enable the extensions one by one to identify the conflicting extension.


4. Clear Browser Cache and Cookies

For Chrome and Edge:

Press:

Ctrl + Shift + Delete

Select:

  • Cookies and other site data
  • Cached images and files
  • Time range: All time

Clear the data and restart the browser.

For Firefox:

Press:

Ctrl + Shift + Delete

Clear:

  • Cookies
  • Cache

Then restart Firefox.


5. Flush the Windows DNS Cache

Open Command Prompt as Administrator and run:

ipconfig /flushdns

You should see a confirmation that the DNS Resolver Cache was successfully flushed.

Test the login again.


6. Check Windows Proxy Settings

Go to:

Settings → Network & Internet → Proxy

Confirm whether a proxy is configured.

If a proxy is not required by your organization, temporarily disable:

  • Use a proxy server
  • Setup script

Then test again.


7. Check VPN Connections

Temporarily disconnect from any third-party VPN and test again except for Timus Application.

Examples:

  • Cisco AnyConnect
  • FortiClient
  • GlobalProtect
  • Zscaler
  • NordVPN
  • ExpressVPN
  • Other corporate or personal VPN clients

If the login works without the VPN, review the VPN's DNS, routing, proxy, and security configuration.


8. Check Antivirus / EPP / Security Software

Temporarily test without relevant web security features, where permitted.

Review features such as:

  • Web Protection
  • Network Protection
  • HTTPS Inspection
  • SSL Inspection
  • DNS Filtering
  • Browser Protection
  • Web Filtering

Examples include:

  • Microsoft Defender for Endpoint
  • SentinelOne
  • CrowdStrike
  • Sophos
  • Bitdefender
  • Webroot
  • Trend Micro

After disabling the relevant feature temporarily, restart the browser and test again.


9. Check Firewall or DNS Filtering

Verify that the following domains are not being blocked:

google.com

www.google.com

gstatic.com

www.gstatic.com

recaptcha.net

www.recaptcha.net

Also review:

  • DNS filtering logs
  • Firewall logs
  • Web filter logs
  • Proxy logs
  • SSL inspection logs

10. Test from Another Network

Connect the Windows device to a mobile hotspot and test again.

If it works from the hotspot but not from the original network, investigate:

  • Firewall
  • DNS filtering
  • Proxy
  • SSL inspection
  • Network security policies

macOS Troubleshooting

1. Check Your reCAPTCHA Score

Open:

https://antcpt.com/score_detector/

Take a screenshot of the result and provide it to Support.


2. Test in Private Browsing Mode

Safari

  1. Open Safari.
  2. Select File.
  3. Click New Private Window.
  4. Open the affected login page.
  5. Test the login again.

Shortcut:

Command + Shift + N

Google Chrome

  1. Open Chrome.
  2. Click the three dots.
  3. Select New Incognito Window.
  4. Test the login.

Shortcut:

Command + Shift + N

Mozilla Firefox

  1. Open Firefox.
  2. Open the menu.
  3. Select New Private Window.
  4. Test again.

Shortcut:

Command + Shift + P


3. Disable Browser Extensions Temporarily

Safari

Go to:

Safari → Settings → Extensions

Disable all extensions temporarily.

Chrome

Enter:

chrome://extensions

Disable all extensions temporarily.

Firefox

Enter:

about:addons

Disable the installed extensions temporarily.

Restart the browser and test again.


4. Clear Browser Cache and Website Data

Safari

Go to:

Safari → Settings → Privacy → Manage Website Data

Remove the affected website data.

You can also clear history from:

Safari → Clear History

Chrome

Press:

Command + Shift + Delete

Clear:

  • Cookies and other site data
  • Cached images and files

Firefox

Press:

Command + Shift + Delete

Clear cookies and cache.


5. Flush the macOS DNS Cache

Open Terminal and run:

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Enter the macOS administrator password when prompted.

No confirmation message may be displayed. This is normal.

Test again afterward.


6. Check macOS Proxy Settings

Go to:

System Settings → Network

Select the active network connection.

Then go to:

Details → Proxies

Review whether any of the following are enabled:

  • Web Proxy (HTTP)
  • Secure Web Proxy (HTTPS)
  • Automatic Proxy Configuration

If your organization does not require them, temporarily disable them and test again.


7. Check VPN and Network Filters

Go to:

System Settings → Network → VPN & Filters

Review any active:

  • VPN clients
  • Content filters
  • Network filters
  • Security extensions

Temporarily disconnect or disable them where permitted.

Examples may include:

  • Cisco Secure Client
  • FortiClient
  • GlobalProtect
  • Zscaler
  • CrowdStrike network extensions
  • Sophos
  • SentinelOne
  • Web filtering agents

Then test again.


8. Check Privacy and Security Software

Some macOS security products install Network Extensions or Content Filters that can inspect HTTPS traffic.

Review whether the device has:

  • Web filtering
  • HTTPS inspection
  • DNS filtering
  • Content filtering
  • Network security extensions

Temporarily bypass the affected device/user from these policies and test again.


9. Check DNS Configuration

Go to:

System Settings → Network → Active Connection → Details → DNS

Review the configured DNS servers.

If your environment uses a DNS filtering service, confirm that reCAPTCHA-related domains are allowed.

Required domains should include:

google.com

www.google.com

gstatic.com

www.gstatic.com

recaptcha.net

www.recaptcha.net


10. Test from Another Network

Connect the Mac to a mobile hotspot and test the login again.

If the issue does not occur on the hotspot, the problem is likely related to the original network configuration.


Information to Provide to Support Team

If the issue continues on either Windows or macOS, please provide:

  • Screenshot of the reCAPTCHA Score Detector
  • Operating system and version
  • Browser name and version
  • Public IP address
  • Date and approximate time of the failed login
  • Time zone
  • Whether the device is physical or virtual
  • Installed browser extensions
  • Antivirus/EPP/security product
  • DNS filtering product
  • Firewall product
  • Whether SSL inspection is enabled
  • Whether the issue occurs in private browsing mode
  • Whether the issue occurs in multiple browsers
  • Whether the issue occurs on another network or mobile hotspot

This information will help determine whether the reCAPTCHA traffic is being blocked, modified, filtered, or affected by the network or endpoint security configuration.

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