Syntorial is hanging or crashing on startup

Written By Joe Hanley (Super Administrator)

Updated at April 20th, 2026

Table of Contents

Solution #1: Reboot your computer Solution #2: Delete UsersMaster Solution #3: Windows MOTU Solution #4: Disconnect Audio Devices Solution #5: Do a clean reinstall of Syntorial If none of the above solutions work:

Please try the following solutions in order:

Solution #1: Reboot your computer

Solution #2: Delete UsersMaster

Mac

Open Finder
From the "Go" menu at the top of your screen select "Go To Folder..."
Paste in "/Library/Application Support/Syntorial"
Delete any file that has "UsersMaster" in the name
Repeat step 2-4 using this path: "~/Library/Application Support/Syntorial"
Open Syntorial
If it succeeds, it will eventually ask you to make a New User. If you already have an existing user, make a new temporary one. Then go into the File menu, select Load User, and load your previous one.

Windows

Enable hidden files by going into your Control Panel, clicking Appearance and Personalization, and then clicking Folder Options. Click the View tab. Under Advanced settings, click Show hidden files and folders, and then click OK.
Go to “C:\Program Data\Syntorial”
Delete any file that has "UsersMaster" in the name
Go to "C:\Users\[username]\AppData\Roaming\Syntorial"
Delete any file that has "UsersMaster" in the name
Open Syntorial
If it succeeds, it will eventually ask you to make a New User. If you already have an existing user, make a new temporary one. Then go into the File menu, select Load User, and load your previous one.

Solution #3: Windows MOTU

Are you on Windows and using a MOTU M2 or M4 audio interface? Go into the MOTU's settings and turn off the "Use lowest latency safety offsets" option.

Solution #4: Disconnect Audio Devices

Disconnect all audio devices from your computer
Restart your computer
Without reattaching any devices, launch Syntorial
If it works, re-connect your audio devices
In Syntorial, go into the Options menu at the top of your screen and select MIDI And Audio Settings.
Select your desired Audio Output
Do a lesson in Syntorial
Close and re-open Syntorial

Solution #5: Do a clean reinstall of Syntorial

Completely uninstall Syntorial: How do I uninstall Syntorial?
Download the latest version (log into your online account and select Downloads in the Syntorial section)
Run the installer

If none of the above solutions work:

Use the Contact Us button at the top of this page to reach out to us. Collect, zip and attach the following files:

Syntorial's StartupLog.txt located in Documents/Syntorial
If Syntorial crashes during startup (instead of hanging) send us a Crash Report.
A screenshot of your audio device configuration
1. Mac:
  - Go into Applications/Utilities
  - Open Audio MIDI Setup
  - Make sure the Audio Devices window is visible (if not, enable it from the Windows menu at the top of your screen)
  - Take a screenshot
2. Windows
  - Right click the sound icon in your system tray (or task tray)
  - Select “Open Sound Settings”
  - Select “Manage Sound Devices”
  - Make sure all outputs are visible
  - Take a screenshot

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