Troubleshooting network errors

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This guide helps resolve "Network error" messages that may occur when uploading files to the Cue platform (e.g., CSV files for WhatsApp broadcasts, documents for AI Agents).

Symptoms

  • Error message: "Network error. Please check your network connection or Firewall/VPN settings"
  • File uploads fail or time out
  • The issue typically occurs on corporate networks or managed devices
  • The same action may work on a personal device or home network

Why This Happens

Cue uses modern HTTP/2 connections for improved performance and security. Some corporate security tools, firewalls, or network configurations may not be fully compatible with HTTP/2, causing file uploads to fail.

Quick Checks (For Users)

Before involving your IT team, try these steps:

  1. Try a different browser - Test in Chrome, Firefox, or Edge
  2. Try incognito/private mode - This disables browser extensions that may interfere
  3. Try a different network - If possible, test on mobile data or a different Wi-Fi network
  4. Disable browser extensions temporarily - Ad blockers or security extensions can interfere
  5. Check your VPN - If connected to a corporate VPN, try disconnecting temporarily

If the upload works on a different network or device, the issue is likely related to your corporate security configuration.

Information for IT/Security Teams

If the user has confirmed the issue is network-related, please share this section with your IT team.

The Issue

Cue's platform uses HTTP/2 over TLS 1.2+ for all connections. Some security configurations may interfere with HTTP/2 connections, particularly:

  • SSL/TLS inspection (MITM proxies)
  • Web filtering proxies
  • Next-generation firewalls with deep packet inspection
  • Endpoint protection software

Domains to Allowlist

Please ensure the following domains are permitted through your firewall, proxy, and security tools:

Domain Purpose
app.cuedesk.com Main application
*.cuedesk.com All Cue services

Port: 443 (HTTPS)

Protocol: HTTP/2 over TLS 1.2 or higher

Common Security Tools That May Require Configuration

The following tools have been known to require configuration adjustments for HTTP/2 compatibility:

Tool Category Recommendation
Zscaler Cloud security proxy Add *.cuedesk.com to SSL inspection bypass list
Cisco Umbrella DNS/Web security Allowlist Cue domains; check SSL decryption policies
Palo Alto Networks Next-gen firewall Ensure HTTP/2 is permitted; check SSL decryption rules
Fortinet FortiGate Firewall/UTM Verify HTTP/2 support in web filter profile
Sophos Endpoint/Firewall Add exception for Cue domains in web filtering
CrowdStrike Falcon Endpoint protection Check web filtering policies
Microsoft Defender for Endpoint Endpoint protection Review network protection settings
Symantec/Broadcom WSS Web security service Configure SSL inspection bypass

SSL/TLS Inspection Considerations

If your organisation performs SSL/TLS inspection (decrypting HTTPS traffic for scanning), this can interfere with HTTP/2 connections. Options include:

  1. Bypass SSL inspection for Cue domains - Add *.cuedesk.com to your inspection bypass list
  2. Ensure your proxy supports HTTP/2 - Some older proxy configurations downgrade connections to HTTP/1.1, which may cause issues with file uploads

Firewall Rules

Ensure outbound connections are permitted:

Source: User devices
Destination: *.cuedesk.com
Port: 443
Protocol: TCP (HTTPS/HTTP/2)
Action: Allow

Browser and System Requirements

  • TLS Version: 1.2 or higher (TLS 1.3 recommended)
  • HTTP/2 Support: Enabled (default in modern browsers)
  • Supported Browsers: Chrome, Firefox, Edge, Safari (latest versions)

Workarounds

While your IT team investigates, these temporary solutions may help:

  1. Use a non-corporate device - If permitted by your organisation's policies
  2. Use mobile data - Temporarily disconnect from corporate Wi-Fi
  3. Request a temporary VPN bypass - Ask IT for a temporary exception

Still Having Issues?

If you've tried the above steps and are still experiencing problems:

  1. Note the exact time the error occurred
  2. Take a screenshot of the error message
  3. Note which browser and version you're using
  4. Contact Cue support with these details

Your IT team can also contact Cue support for technical assistance with firewall and proxy configuration.

Technical Background

Why HTTP/2?

HTTP/2 provides significant performance improvements for web applications:

  • Multiplexing - Multiple requests over a single connection
  • Header compression - Reduced overhead
  • Binary protocol - More efficient than HTTP/1.1 text-based protocol

These improvements are particularly beneficial for file uploads and real-time messaging applications like Cue.

Why Some Security Tools Interfere

Many security tools were designed for HTTP/1.1 and may:

  • Downgrade connections to HTTP/1.1 during inspection
  • Not properly handle HTTP/2 multiplexed streams
  • Introduce latency that causes upload timeouts
  • Strip or modify headers required for HTTP/2

Modern security tools generally support HTTP/2, but may require explicit configuration to handle it correctly.