Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:13.0a1) Gecko/20120210 Firefox/13.0a1 It started appearing sometime between 05.01.2012-20.01.2012, a white bar without any functionality in the bottom of the window. It's not limited to any specific websites, once it appears it's mostly on them all. I found out that minimizing and maximizing the window gets rid of it, however this "workaround" applies only to the actual session. Meaning that once I sometime turn Nightly off, and then sometime later use it again I eventually end up getting the very same white bar.. Screenshot: http://i40.tinypic.com/14905dy.jpg

Does the issue still occur if you start Firefox in Safe Mode? https://support.mozilla.com/en-US/kb/Safe+Mode Do you get a menu if you right click on the bar?

I see the same thing on Mac OS X: Build identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:13.0) Gecko/20100101 Firefox/13.0 Seeing it on Google Reader most obviously. Seems the screenshots are of Google as well, so it might be an issue with Google. I'm posting a screenshot attachment too. (Minimizing/maximizing/etc doesn't do anything)

The content of attachment 625334 [details] has been deleted by Dave Miller [:justdave] <justdave@mozilla.com> who provided the following reason: Deletion of unsanitized data requested by uploader The token used to delete this attachment was generated at 2012-05-18 19:20:54 PDT.

I see the same thing on Mac OS X: Build identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:13.0) Gecko/20100101 Firefox/13.0 Seeing it on Google Reader most obviously. Seems the screenshots are of Google as well, so it might be an issue with Google. I'm posting a screenshot attachment too. (Minimizing/maximizing/etc doesn't do anything)

I can confirm this bug Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:19.0) Gecko/19.0 Firefox/19.0 buildID: 20121104090239 so odd it not happens in Safe Mode, in normal mode it happens every time, even with disabled addons,plugins, HW Acc or just same disabled Azure...

I cannot yet confirm; however, those of you who can should use DOM Inspector to identify the element.

It looks like a ghost add-on bar, same height and position.

Could you try to enable then disable the add-on bar to see if the shadow disappears?

(In reply to IU from comment #8) > I cannot yet confirm; however, those of you who can should use DOM Inspector > to identify the element. How can I do that? "Find a node to inspect by clicking on it" don't work on browser bars. (In reply to Loic from comment #10) > Could you try to enable then disable the add-on bar to see if the shadow > disappears? Yes, white blank bar disappears. It also disappear when I enable/disable other bars or just open "Customize..." window and go back to Fx. It happens also with enabled or disabled add-on bar.

(In reply to Virtual_ManPL [:Virtual] from comment #11) > How can I do that? "Find a node to inspect by clicking on it" don't work on > browser bars. I'm not sure if this extension works with current builds but it does make inspecting chrome elements easier: https://addons.mozilla.org/en-US/firefox/addon/inspect-context/

(In reply to IU from comment #12) > I'm not sure if this extension works with current builds but it does make > inspecting chrome elements easier: > https://addons.mozilla.org/en-US/firefox/addon/inspect-context/ This works flawlessly! Thank you! FYI Steps to easy reproduce this bug: 1. Set you homepage to http://forums.mozillazine.org/viewforum.php?f=23 2. Restart browser

I'm not able to reproduce it. Are you able to reproduce it with a new profile?

Yep. Using "Reset Nightly" button in about:support or deleting Mozilla folders in C:\Users\USER_NAME\AppData\Roaming\Mozilla C:\Users\USER_NAME\AppData\Local\Mozilla don't help... ;/

I also confirm.I started seeing this with the 2012-11-06 nightly.On my dirty profile it seems to be caused by Lastpass and X-Notifier.Either of those causes the bug.Disabling those addons fixes it and the bar does not show.I then tried clean profile and see this bar with no addons installed every time.As the OP stated it appears only in maximized mode and only when Nightly loads a single tab on startup.Also enabling and disabling the addon bar removes the ghost bar.

I think there is a different issue with a new profile and no add-on, see bug 809258. In bug 809258 the culprit is the Social API but I'm not sure the Social API was implemented when the OP reported the issue in Firefox 13. So in this current bug, the issue is maybe due to an add-on. But he did'nt test in safe mode or with a new profile, so it's hard to debug and find the buggy add-on.

Yep, our bug is probably bug #809258. Thanks for info.

Btw on my current Nightly profile it seems that 'X-notifier','Lastpass' and 'Wiktionary and Google Translate' addons seem to trigger the white bar.

(In reply to nasko_naskov from comment #19) > Btw on my current Nightly profile it seems that 'X-notifier','Lastpass' and > 'Wiktionary and Google Translate' addons seem to trigger the white bar. Does this white bar disappear if you test with a new profile and all these add-ons disabled?

No.With new profile after the restarts to accept/deny "know your rights" and "submit performance data" popups and with no addons the bar appears again.

(In reply to nasko_naskov from comment #21) > No.With new profile after the restarts to accept/deny "know your rights" and > "submit performance data" popups and with no addons the bar appears again. How is that possible?

nasko_naskov is probably taking about bug #809258 like me before. This bug can be closed as WFM for time being.

Yes, especially because Social API is not present in FF13 and the initial reporter doesn't participate to the discussion.