Fix Microsoft Intune Tunnel Upgrade Error v20260129.1 – Linux Servers 2026

This is the official Microsoft remediation script for fixing upgrade issues with version 20260129.1.

1. Connect to your Linux Tunnel server via SSH with administrative privileges
2. Download the official patch script from Microsoft:
   

   wget https://download.microsoft.com/download/tunnel/mstunnel-patch-2602.sh

3. Verify the script integrity by checking the hash:
   

   sha256sum mstunnel-patch-2602.sh

4. Make the script executable:
   

   chmod +x mstunnel-patch-2602.sh

5. Stop the Microsoft Tunnel service before running the patch:
   

   sudo systemctl stop mstunnel

6. Run the remediation script with sudo privileges:
   

   sudo ./mstunnel-patch-2602.sh

7. Monitor the script output for any errors or completion messages
8. Restart the Tunnel service after successful patch completion:
   

   sudo systemctl start mstunnel

If the patch script is unavailable, manually verify and reset the Tunnel service configuration.

1. Check the current Tunnel version and service status:
   

   sudo mstunnel --version
   sudo systemctl status mstunnel

2. Verify the installed package version:
   

   dpkg -l | grep mstunnel

3. Check for corrupted configuration files:
   

   sudo find /etc/mstunnel -name "*.conf" -exec ls -la {} \;

4. Stop all Tunnel-related services:
   

   sudo systemctl stop mstunnel
   sudo systemctl stop mstunnel-agent

5. Clear temporary upgrade files:
   

   sudo rm -rf /tmp/mstunnel-upgrade/*
   sudo rm -rf /var/cache/mstunnel/upgrade/*

6. Reset service configuration to defaults:
   

   sudo systemctl reset-failed mstunnel
   sudo systemctl daemon-reload

7. Restart services in the correct order:
   

   sudo systemctl start mstunnel-agent
   sudo systemctl start mstunnel

Manually force the upgrade to a newer version that resolves the known issue.

1. Add the Microsoft Tunnel repository if not already configured:
   

   curl -sSL https://packages.microsoft.com/keys/microsoft.asc | sudo apt-key add -
   echo "deb [arch=amd64] https://packages.microsoft.com/repos/tunnel-prod/ focal main" | sudo tee /etc/apt/sources.list.d/mstunnel.list

2. Update the package repository:
   

   sudo apt update

3. Check available Tunnel versions:
   

   apt list --upgradable | grep mstunnel

4. Stop the current Tunnel service:
   

   sudo systemctl stop mstunnel

5. Force install the latest version:
   

   sudo apt install --reinstall mstunnel=20260330.1-1

6. Reconfigure the Tunnel service:
   

   sudo dpkg-reconfigure mstunnel

7. Start the updated service:
   

   sudo systemctl start mstunnel
   sudo systemctl enable mstunnel

8. Verify the upgrade completed successfully:
   

   sudo mstunnel --version
   sudo systemctl status mstunnel

If other methods fail, perform a clean reinstall while preserving your existing configuration.

1. Back up the current Tunnel configuration:
   

   sudo cp -r /etc/mstunnel /etc/mstunnel.backup
   sudo cp /var/lib/mstunnel/server.conf /var/lib/mstunnel/server.conf.backup

2. Export current certificate and key files:
   

   sudo tar -czf mstunnel-certs-backup.tar.gz /etc/ssl/certs/mstunnel* /etc/ssl/private/mstunnel*

3. Stop and disable the Tunnel service:
   

   sudo systemctl stop mstunnel
   sudo systemctl disable mstunnel

4. Completely remove the existing installation:
   

   sudo apt remove --purge mstunnel mstunnel-agent
   sudo rm -rf /etc/mstunnel /var/lib/mstunnel

5. Clean package cache and dependencies:
   

   sudo apt autoremove
   sudo apt autoclean

6. Reinstall the latest Tunnel version:
   

   sudo apt update
   sudo apt install mstunnel

7. Restore the backed-up configuration:
   

   sudo cp -r /etc/mstunnel.backup/* /etc/mstunnel/
   sudo cp /var/lib/mstunnel/server.conf.backup /var/lib/mstunnel/server.conf

8. Restore certificates:
   

   sudo tar -xzf mstunnel-certs-backup.tar.gz -C /

9. Start and enable the service:
   

   sudo systemctl enable mstunnel
   sudo systemctl start mstunnel

For persistent issues, analyze system logs and perform advanced diagnostics.

1. Enable detailed logging for the Tunnel service:
   

   sudo systemctl edit mstunnel

   Add the following lines:
   

   [Service]
   Environment="MSTUNNEL_LOG_LEVEL=debug"

2. Check system logs for upgrade-related errors:
   

   sudo journalctl -u mstunnel -f --since "1 hour ago"
   sudo tail -f /var/log/mstunnel/server.log

3. Analyze package manager logs:
   

   sudo grep -i mstunnel /var/log/dpkg.log
   sudo grep -i mstunnel /var/log/apt/history.log

4. Check disk space and permissions:
   

   df -h /var /tmp /etc
   sudo find /etc/mstunnel -type f -exec ls -la {} \;

5. Verify network connectivity to Microsoft services:
   

   nslookup packages.microsoft.com
   curl -I https://packages.microsoft.com/repos/tunnel-prod/

6. Run system diagnostics:
   

   sudo systemd-analyze verify mstunnel.service
   sudo systemctl list-dependencies mstunnel

7. Generate a comprehensive diagnostic report:
   

   sudo mstunnel --diagnostic-report > tunnel-diagnostic-$(date +%Y%m%d).txt