QZ Tray not connecting or printer printing blanks

Resolving QZ Tray “Not Connected” / Printing Issues (Chrome & Chromium Browsers – 2026+)

🧠 Overview

Due to recent browser security updates (Local Network Access – LNA), QZ Tray may fail to connect to the browser, resulting in:

• “Not Connected” status
• Printers not appearing
• Print jobs are not executing

This guide outlines steps to diagnose and resolve these issues.

⚠️ Symptoms

Users may report:

• QZ Tray shows “Not Connected”
• The printer does not appear in Flourish
• Print jobs do nothing
• demo.qz.io fails to connect
• The issue occurs on one workstation but not others

🔍 Root Cause

Modern browsers (Chrome, Edge) now block connections to local applications (like QZ Tray) by default.

Users must explicitly allow permission for:

• “Access other apps and services on this device”
• “Access devices on your local network”

Failure to allow this = QZ Tray cannot connect.

🛠️ Step-by-Step Resolution

1️⃣ Confirm QZ Tray is Running

• Check system tray (bottom-right corner on Windows / top menu on Mac)
• If not running:
  • Launch QZ Tray manually
  • Restart if already open

2️⃣ Check Browser Connection Status

• Open Flourish
• Check QZ Tray status:
  • Connected → proceed to Step 6
  • Not Connected → continue below

3️⃣ Check for Permission Pop-Up (CRITICAL)

When opening Flourish, look for a browser prompt:

“This site wants to access other apps/services on this device”

✅ Click Allow

⚠️ If dismissed 3 times, the browser may auto-block

4️⃣ Reset Blocked Permissions

Chrome / Edge:

1. Click the lock icon in the address bar
2. Go to Site settings
3. Find:
   • Local network access / Insecure content
4. Set to Allow
5. Refresh the page

5️⃣ Restart Everything

• Close the browser completely
• Quit QZ Tray
• Reopen QZ Tray
• Reopen the browser and Flourish

6️⃣ Test Connection

• Go to: https://demo.qz.io
• Click “Connect”

Expected result:

• QZ Tray connects successfully
• Printer list populates

❌ If Still Not Working:

7️⃣ Try Another Browser

• Switch between:
  • Chrome
  • Microsoft Edge

⚠️ Note: One browser may work temporarily due to cached permissions

8️⃣ Clear Browser Cache

• Clear cache + cookies

• Restart browser

9️⃣ Reinstall QZ Tray

• Uninstall QZ Tray
• Reinstall latest version (or previously working version)
• Restart machine

🔟 Verify Printer

• Print test page directly from computer
• Confirm:
  • Printer works outside QZ Tray
  • Drivers are installed

🔧 Advanced Troubleshooting:

🌐 Check Localhost Permissions

Ensure browser allows:

• Insecure localhost connections
• Invalid certificates (if applicable)

🖥️ Check for Machine-Specific Issues

If other POS systems work:

• Issue is likely local to that workstation

Possible causes:

• Cached blocked permissions
• Security software interference

• Corrupt browser profile

🏢 Corporate / IT Environments

If applicable:

• IT can whitelist your domain using browser policies:
  • Chrome: LocalNetworkAccessAllowedForUrls

⚠️ Known Issues (2026+)

• Chrome/Edge updates may:
  • Reset permissions
  • Re-trigger connection issues
• Edge may stop working after initially working
• Chrome may show “Connected” but still fail to print

🚨 When to Escalate

Escalate to support if:

• demo.qz.io cannot connect
• The issue persists across browsers
• The issue affects multiple machines
• All steps above have been completed

✅ Key Takeaway

This issue is not a printer or QZ Tray bug — it is caused by browser security changes requiring manual permission for local connections.