If Syntorial opens to the "Select User" screen and no users are listed, or you see a message like "not a Syntorial user file, or is corrupt," here's what's going on and how to fix it.

What's happening

Syntorial keeps track of your lesson progress in a small folder inside your computer's Documents folder. If that folder goes missing, gets moved, or ends up in a bad state, Syntorial won't be able to find your progress when it starts up. That's what causes the empty user list or the corrupt file message.

There are two common causes:

1. Cloud backup services. If you have iCloud Drive (Mac) or OneDrive (Windows) set up to back up your Documents folder, they can sometimes move your Syntorial progress files off your computer and into the cloud only, or shuffle them around in a way that Syntorial doesn't expect. When that happens, Syntorial looks in Documents and doesn't find what it needs.
2. A one-off glitch. Sometimes the progress files just get into a bad state on their own, with no cloud service involved at all.

Fix 1: If you use iCloud Drive on a Mac

Check whether "Desktop & Documents Folders" syncing is turned on in your iCloud settings. If it is, you have two options:

• Keep it on, but protect your Syntorial folder. Open Finder, go to your Documents folder, find the Syntorial folder, right-click it, and choose the option to keep it downloaded to your Mac at all times (rather than letting iCloud offload it to the cloud only).
• Turn off Documents syncing entirely. In System Settings, under your Apple ID's iCloud settings, find the Drive options and turn off syncing for Desktop & Documents Folders. Keep in mind this affects every app that stores files in your Documents folder, not just Syntorial.

(Exact menu names can shift slightly between macOS versions. If you don't see these exact labels, look for "iCloud Drive," then "Desktop & Documents Folders" or similar, in your Apple ID/iCloud settings.)

Fix 2: If you use OneDrive on Windows

If OneDrive is backing up your Documents folder, either turn off Documents backup in OneDrive's settings, or set your Syntorial folder specifically to always stay on your device rather than being offloaded to the cloud.

Fix 3: General recovery (works even if you don't use cloud syncing)

If the steps above don't apply to you, or you've already tried them and are still stuck, this usually resolves it:

1. Quit Syntorial completely.
2. Open your Documents folder and delete the Syntorial folder you find there.
3. Reinstall Syntorial and launch it again.
4. Sign in with your Syntorial account when it opens.

This clears out whatever got into a bad state and lets Syntorial start fresh.

Will you lose your progress? If you're signed in to a Syntorial account, your progress is backed up to that account. When you reinstall and sign back in while connected to the internet, Syntorial pulls your progress down automatically, so this is safe. If you're using the free demo or you've never signed in, your progress lives only on your computer, so copy the Syntorial folder somewhere safe before deleting it (or reach out to us first and we'll help).

Still stuck?

If none of this fixes it, contact us and let us know your operating system, your Syntorial version, and whether you use iCloud or OneDrive. That'll help us figure out what's different about your setup.