Part 1 - Reset your Firefox Sync account
   Part 2 - Re-add your devices

   At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP) and then click Options.
   Once the options window opens, click on the Sync tab.
   In the Sync tab click on Manage Account and select My Sync Key
   A new window will open displaying a Sync Key - ignore that and click Generate
   A new Sync Key will be made for you. Please take a moment to print it out or save it on your computer. Then click Change Sync Key

I keep getting this error message "Sync encountered an error while syncing: Unknown error. Sync will automtaically retry this action." I tried solution suggested at https://support.mozilla.com/en-US/kb/Replace%20your%20Sync%20information. Firefox Help Welcome, peterhw. Inbox | Dashboard | Sign Out Replace your Sync information If you are having trouble getting all of your desktop information to show up on your other devices, this article will show you how to fix that by replacing the sync data you have on the server with a new copy from your desktop. Table of Contents Part 1 - Reset your Firefox Sync account Part 2 - Re-add your devices Part 1 - Reset your Firefox Sync account Warning: This will erase all of your data stored on the server. Data loss is possible. At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP) and then click Options. Once the options window opens, click on the Sync tab. In the Sync tab click on Manage Account and select My Sync Key A new window will open displaying a Sync Key - ignore that and click Generate A new Sync Key will be made for you. Please take a moment to print it out or save it on your computer. Then click Change Sync Key I aborted after about 15 hours. I only have a single desktop. I have updated my mobile phone - but thought was Nokia suite (i.e. nothing to do with FireFox). So not sure what it is trying to sync, whether it has always tried to do this and until recently been successful. The 'problem' doesn't seem to have any ill effects but would like to get rid of error.