First off I accidently hit the "I have the problem too" button, which I don't but, I don't use sync very often. I can't honestly say how to exactly but, maybe run through a few trouble shooting techniques. Try here https://support.mozilla.org/en-US/kb/firefox-sync-troubleshooting-and-tips if this doesn't help (I have tried searching for a while to find a easy solution) If you were signed in and your settings and preferences were saved then it should work. Sometimes it doesn't. Also please consider reporting this as a bug (I would as it may be a repeat issue as this release is kinda still fresh) You can find that out here https://support.mozilla.org/en-US/kb/how-do-i-submit-bug-firefox-sync

Okay, I just found out what happened, I changed my password.

I didn't know when you change your password, Mozilla deletes all synced data from their servers.

This very stupid of Mozilla to have it setup this way.

Mozilla should have warn me before I change my password All my synced data will be deleted.

If I had known this, I wouldn't have changed my password, or would have saved my bookmarks to my PC first.

"Mozilla, Please warn people before they change their sync password that all synced data will be deleted."

Thank You!

The encryption 'key' that Sync uses is derived from the user's Password; change that and the save data is worthless - it can't be decrypted!

This message appears when the user starts to change their Sync password. "Warning: Any data you have on the server will be erased when you reset your password. Your other devices will stop synchronizing unless you update them with the new password."

https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information

Oh, another thing - Sync isn't intended to be used as a backup medium for one device; like to store user data while that one device is being formatted. Its purpose is to synchronize select Firefox data across multiple devices.

And the only time I have heard about "this" happening when Sync was used as intended, is when the user formatted both PC's at the same time and then changed the Sync Password; eliminating the chance of recovering his data from the 2nd device.

@the-edmeister

Yes, I read that here "https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information#w_iaove-forgotten-my-firefox-account-password-ae-how-do-i-reset-it"

After the fact but, when I changed the password there was no warning message whatsoever. If there had been one like I said before I wouldn't have changed it then, or would saved my bookmarks to my PC then changed it.

I do know what syncing is for, I have multiple devises. that is why I set up a syncing account.

I Thank You For Your Imput

This what I just got when I went to change my Sync Password. Chopped off the bottom to not reveal my email address.

As far as using multiple devices with Sync - you haven't lost any data. Your data should be on all the other devices. Just connect another desktop / laptop device with the new Sync Password and all your data should be sync'd back to the Sync server. Mobile devices won't have ALL your data; certain types of data may differ from the desktop / laptop devices.

Thank you for the screen capture. I did not get that message, I really wished I had.

All the bookmarks are gone from the other PC's I had to use the new password, when I did it reset everything like if it was a freshly installed Browser.

It never synced to my iPhone's Firefox browser but, I hardly ever used the internet on my iPhone. So, it didn't matter enough for me to report it.

@the-edmeister

Could Adblock plus have blocked that message?

Some information of how Sync works:

The Sync service uses a sync key to encrypt data locally before uploading to the Sync server. This Sync key is generated internally from the password of your Firefox account, so you do not need to worry about it. Without the correct password it isn't possible to generate the correct Sync key and decrypt data retrieved from the Sync server. The Sync key changes when you change the password of the Firefox account and you lose all data stored on the Sync server when you change the password of the Sync account. Other connected devices use the same name and password to log in to the Firefox Sync account, so they can decrypt data downloaded from the server locally. As long as you choose a strong password and you keep it to yourself then your data is safe.

• https://blog.mozilla.org/services/2014/04/30/firefox-syncs-new-security-model/

Bobcat said

@the-edmeister Could Adblock plus have blocked that message?

No. That message would come from within Firefox after a connection was made with the Sync server. If ABP blocked anything, a message would have appeared about Firefox not being able to make a connection repeatedly after using "Try again"; instead of that specific message.

see the screenshot: I always get this the first time I try to reconnect to Sync, and need to use the Try again button.