Recovering from "Replace your database and start syncing" error

One of the frequently asked questions that our Support team gets is “Why did I get a message asking to Replace your database and start syncing?” So I thought I’d thought I’d share the answer and the options for handling it here:

There are a few reason you may get this prompt. In general the reason is that OmniFocus thinks the local copy of the database and the server’s copy are too different to sync them. A few reasons why this might happen are:

  • If you’ve never synced that device.
  • If that device hasn’t synced in more than 3 weeks.
  • If you switch sync accounts.
  • If you’ve turned sync off and back on.

Once you get the prompt OmniFocus won’t be able to sync until you make a choice:

Option 1: Keeping the sync database

Choosing Keep Sync Database is usually the simplest/easiest option. When you do that—if you’re running OmniFocus 2.15 for iOS or later—the device’s current database will be preserved on the device as a backup for about a day and the server’s database will become the active database. If that turns out to be undesirable you can restore the backup, but you’ll want to do that somewhat quickly as backups get overwritten every day.

(If you’re running an older version there are no local backups.)

Option 2: Keeping the device database

If you know the device’s data is the most up-to-date, you can Cancel the replace prompt and tell the device to send its data to overwrite the data on the server. To do that, reveal the secret bar and tap Settings ▸ Replace Sync Database. When you do that, the server’s data will also be preserved as a backup on your device for about a day.

Restoring a backup

To see your backups, reveal the secret bar and tap Settings ▸ Backups. Tap the date the backup was taken to view information about it. To restore the backup and overwrite the server database tap Revert to This Backup.

Merging different databases

OmniFocus isn’t currently able to merge two databases that it thinks are too different to sync. However, if you have access to OmniFocus for Mac (even the free trial) you could manually merge the data yourself. For help doing that email us!


I’ve encountered the “Replace your database and start syncing?” situation twice now, upon completely restoring my Mac from bootable backup. Why might that be happening?



Because the other clients keep in mind all the changes that have been made to the database of one client hasn’t been synching lately.

Once that client comes back online, all the data is being used to perform the exact same changes on that other client as well.

Afterwards, there is no history of what has been changed where, so if you reset your client to an earlier stage (by restoring a backup), the other clients don’t know what to tell your computer when it asks for updates (to the outdated database from the backup files). That’s why OF will then ask you to just get aboard with what all the other devices agree upon.

That’s how I understand the limitations of how OF syncs. I would love for the sync to be more robust, especially the three week limit that is imposed on how long changes are being stored when a single device hasn’t synced lately, but I don’t think that’s going to be improved anytime soon, unfortunately.