Software⏱️ 3 min read📅 2026-06-15

How to Fix: Any way to resolve the "another window manager is already running" error with dwm in OS X?

Resolving dwm window manager error in OS X Mountain Lion.

Quick Answer: Try running dwm with the -n option to disable notification, or use a different window manager like i3.

📋 Table of Contents

  1. ⚠️ Common Causes
  2. ✅ Best Solutions to Fix It
  3. 💡 Conclusion

The 'another window manager is already running' error occurs when two or more window managers are trying to run at the same time, causing conflicts and preventing either of them from launching properly. This issue primarily affects users who have installed dwm (Dynamic Window Manager) on OS X Mountain Lion.

This error can be frustrating for users as it prevents them from customizing their desktop environment with dwm. However, by following the steps outlined in this guide, you should be able to resolve the issue and get dwm up and running.

⚠️ Common Causes

  • The primary reason why this error happens is due to the way OS X handles window managers. By default, OS X only allows one window manager to run at a time, which can cause conflicts when trying to launch multiple window managers simultaneously. Additionally, some users may have installed other window managers or applications that are also trying to launch and compete for resources.
  • Another possible reason for this error is due to the fact that dwm requires X11 (or xQuartz) to run, but some users may not have properly configured their environment or may be using a conflicting application.

✅ Best Solutions to Fix It

Disable Other Window Managers

  1. Step 1: First, close any other window managers that are currently running. You can do this by closing the terminal windows or using the Command + Q keyboard shortcut to quit the window manager.
  2. Step 2: Next, open a new Terminal window and type 'killall -9 ' (replace '' with the name of the window manager you want to kill). This will force-quit the window manager and allow dwm to run without conflicts.
  3. Step 3: After killing any other running window managers, try launching dwm again by typing 'dwm &' in the Terminal window. If this fails, you may need to restart your system or reinstall dwm.

Disable xQuartz and Reinstall dwm

  1. Step 1: To resolve this issue, you can try disabling xQuartz by deleting its configuration files and then reinstalling dwm. This will ensure that only one window manager is running at a time.
  2. Step 2: First, open the Terminal window and type 'rm -rf /Library/Preferences/com.apple.x11' to delete the xQuartz configuration files. Be careful when using this command as it will remove all xQuartz settings.

💡 Conclusion

By following these steps, you should be able to resolve the 'another window manager is already running' error and get dwm up and running on your OS X Mountain Lion system.

Did this fix your problem?

If not, try searching for specific error codes.

🔍 Search Error Database

❓ Frequently Asked Questions

🛠️ Related Fixes

How to Fix: Pc crashes shortly after launching game (rainbow

Fix Pc crashes shortly after launching game (rainbow six siege). Compl

How to Fix: Installing an APK on a locked down phone

Installing an APK on a locked down phone: Try using a rooted device, e

How to Fix: New PC build- no signal and no clue

Fix New PC build- no signal and no clue. Complete troubleshooting guid