Are you saying that you used Sync to backup your data, in lieu of doing a proper backup?

I not recive data with all plugins and bookmarks... i lost very important thins :(

Hey,

Firefox Sync resets every time I close Firefox

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:

   Click the menu button New Fx Menu and choose Preferences.
   Select the Privacy panel.
   In the Firefox will: menu, select Use custom settings for history and ensure that Clear history when Firefox closes is unchecked.
   If you want or need to keep this setting checked, click the Settings... button next to it and then uncheck Saved passwords in the Data section.

   Close the about:preferences page. Any changes you've made will automatically be saved.

Still the problem remains refer to the article Firefox Sync resets every time I close Firefox

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:

   Click the menu button New Fx Menu and choose Preferences.
   Select the Privacy panel.
   In the Firefox will: menu, select Use custom settings for history and ensure that Clear history when Firefox closes is unchecked.
   If you want or need to keep this setting checked, click the Settings... button next to it and then uncheck Saved passwords in the Data section.

   Close the about:preferences page. Any changes you've made will automatically be saved.

tell us was this helpful to you