Reproducible on: Firefox 31.3.0 ESR, Firefox 34.0.5 and Nightly 36.0a1 across all platforms. STR 1.Launch Firefox with a clean profile. 2.Open the Browser Console. 3.Click Panel Menu and enter Customize mode. 4.Drag the Sync button to toolbar. 5.Select Sign in to Sync from Panel Menu. 6.Log in using a Firefox account. 7.Wait until the Sync icon from toolbar stops from rotating. 8.Click Manage button. 9.Click Disconnect and then Continue button. ER No errors thrown in Browser Console. AR This error is thrown in Browser Console: “1417181196863 Sync.BrowserIDManager ERROR Could not authenticate: no user is logged in Log.jsm:749:0”. Additional notes: - This issue is reproducible on Firefox 31.3.0 ESR (20141125031119), Firefox 34.0.5 (20141126041045) and latest Nightly 36.0a1 (2014-11-27) across Windows 7 x64, Mac OSX 10.9.5 and Ubuntu 12.04 x32.