If you've run into a problem with Firefox Sync, this article will walk you through the most common solutions.
Your devices need to be on the new version of Sync in order for them to share information with each other. If any of your devices are still on the old Sync, you must unlink them before setting them up with the new Sync. Please see Sync your Firefox bookmarks, history, passwords and more for step-by-step instructions.
If you're unable to connect to Firefox Sync because you've lost Sync account information, see I've lost my Firefox Sync account information - What to do.
Passwords will stop syncing in Firefox for Android once the master password has been set. See Using Master Password on Firefox for Android for more info.
If you have more than 5,000 bookmarks in your Firefox profile, Firefox for Android won't sync them. Some limitations in Android and Sync itself make larger quantities of bookmarks unreliable, so this limit is there to protect your data.
This happens when you have Firefox set to delete passwords when it's closed. If you've selected Use custom settings for history in the Privacy panel, you'll need to follow these steps:
If you change your Sync password, you might see this error message on your other devices "Sync encountered an error while connecting: Incorrect name or password." error appears in the bottom error bar. You can update your password on your device by completing the following steps:
To improve the Sync service, the Sync data format may be changed when the latest Firefox version is released. This means that any of your other devices which have not been updated will need to be updated in order to keep syncing. See Update Firefox for more information.
If you see the Cookies are still disabled error message, change your permissions for Firefox Accounts to allow cookies.
Here's how to do it:
If this does not help, please make sure that there are no add-ons blocking cookies for accounts.firefox.com.
For advanced users: Make sure DOM Storage is enabled:
In the address bar, type about:config and press EnterReturn.
If you cannot find your confirmation email when connecting a device for the first time, please first check your spam filters to make sure that the email wasn't marked as spam.
Please wait an hour to try to reset your password or send a new confirmation email to add the new device. In the meantime, please check your spam filters and make sure the email account entered is correct.