CMTrace Open

A free, open-source log viewer and Windows troubleshooting tool. Drop in a log file and start reading — no install wizards, no prerequisites, no license keys.

Built as a modern replacement for Microsoft's CMTrace.exe with added Intune diagnostics, DSRegCmd analysis, and real-time log tailing.

Install

Download the latest release for your platform and run it. That's it — single file, no dependencies.

All releases are signed. The Windows executable is code-signed and the macOS app is notarized.

Startup update checks are disabled by default. Users can opt in from Settings > Updates. Managed Windows deployments can force-disable all app update checks with either installer:

CMTrace-Open_*_x64-setup.exe /S /DisableUpdateChecks
msiexec /i CMTrace-Open_<version>_x64.msi /qn DISABLEUPDATECHECKS=1

The MSI option writes HKLM\Software\CMTrace Open\DisableUpdateChecks=1 and survives uninstall or upgrade until an administrator removes it. The NSIS switch writes the same value under the selected install registry hive. Existing user preferences cannot re-enable update checks on managed devices while this policy is present.

Note: You do not need Node.js, Rust, or any development tools to run CMTrace Open. Just download and run.

Features

Log Viewer

• Auto-detection — automatically identifies CCM, CBS, DISM, Panther, simple, and plain text log formats
• Real-time tailing — live file watching with pause/resume
• Virtual scrolling — smooth performance with 100K+ line files
• Severity color coding — Errors (red), Warnings (yellow), Info (default)
• Find and Filter — Ctrl+F search with F3 navigation; filter by message, component, thread, or timestamp
• Text highlighting — configurable keyword highlighting
• Error code lookup — 120+ embedded Windows, SCCM, and Intune error codes
• Flexible input — open files, folders, drag and drop, or use built-in source presets
• File association — set as default .log file handler on Windows

Intune Diagnostics Workspace

Analyze Intune Management Extension logs without reading raw text line by line.

• Parse a single IME log or an entire IntuneManagementExtension\Logs folder
• Color-coded event timeline for Win32 apps, WinGet apps, PowerShell scripts, remediations, ESP, and sync sessions
• Download statistics with size, speed, and Delivery Optimization percentage
• Summary dashboard with event counts, success/failure rates, and log time span
• Automatic GUID extraction for app and policy identifiers
• Issue clustering with suggested next steps

DSRegCmd Troubleshooting Workspace

Triage Entra join, hybrid join, PRT, MDM, and Windows Hello for Business issues.

• Live capture, paste, text file, or evidence bundle input
• Join posture, failure stage, and capture confidence at a glance
• Issue cards with severity, evidence, and suggested fixes
• Registry-backed Windows Hello for Business policy correlation
• Export as JSON or summary for case handoff

See the DSRegCmd troubleshooting guide for a detailed walkthrough.

Quick Start

1. Download the release for your platform from the Releases page
2. Run the executable — no install required (or use the Windows MSI/NSIS installer)
3. Open a log — drag and drop a file, use File > Open, or use a source preset
4. Explore — use Find (Ctrl+F), Filter, or switch to the Intune/DSRegCmd workspace

Supported Log Formats

Format detection is automatic. Open any log file and CMTrace Open will pick the right parser.

Documentation

Visit the CMTrace Open Wiki for detailed guides:

• Getting Started — installation, first log, basic navigation
• Log Viewer Guide — find, filter, highlight, tailing
• Intune Workspace — IME log analysis and diagnostics
• DSRegCmd Workspace — device join and identity troubleshooting
• FAQ — common questions and answers

Contributing

CMTrace Open welcomes contributions. See CONTRIBUTING.md for development setup, build commands, architecture overview, and coding guidelines.

Disclaimer

CMTrace is a tool developed and distributed by Microsoft Corporation. CMTrace Open is an independent open-source project and is not affiliated with, endorsed by, or connected with Microsoft Corporation. See DISCLAIMER.md for full details.

License

MIT