Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

What are the "layer-xxx" items that appear as open windows in the Window menu bar on Firefox for Mac?

  • 2 replies
  • 12 have this problem
  • 1 view
  • Last reply by SWLinPHX

more options

I am using Firefox with Mac OS X 10.5.8 and I noticed that when I look under the Window menu in Mac menu bar on top, it not only lists all the browser windows, bookmarks library, add-ons manager etc. that I may have open but it frequently shows something like "layer-311930" in the list, as if it was an open (apparently invisible) window. Sometimes more than one of these mysterious "layer-xxxxxx" windows show up under the Window menu. What are they? Is it associated with an add-on or something in FIrefox itself. Thanks for your help.

I am using Firefox with Mac OS X 10.5.8 and I noticed that when I look under the Window menu in Mac menu bar on top, it not only lists all the browser windows, bookmarks library, add-ons manager etc. that I may have open but it frequently shows something like "layer-311930" in the list, as if it was an open (apparently invisible) window. Sometimes more than one of these mysterious "layer-xxxxxx" windows show up under the Window menu. What are they? Is it associated with an add-on or something in FIrefox itself. Thanks for your help.

All Replies (2)

more options

That may be plugin-container processes.
See http://kb.mozillazine.org/Plugin-container_and_out-of-process_plugins

more options

Thanks for your response. However, I see no mention of "layer-xxxxxx" appearing in the Window menu on the Mac menu bar in Firefox and that link says it only applies to Windows and Linux. May I ask what led you to that theory? Thanks...

Modified by SWLinPHX