User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0 (Beta/Release) Build ID: 20140111121932 Steps to reproduce: Go on www.youtube.com by typing it in the address bar Search for anything. Actual results: Error message ASSERTION Adding a child where we already have a child? This may misbehave 'Error' file When Searching on Youtube.com (see attachment) Expected results: The Search should have Completed sucessfully

contents of the debug console at time of crash

[5420] ###!!! ASSERTION: Adding a child where we already have a child? This may misbehave: 'Error', file c:/builds/moz2_slave/m-cen-w32-d-000000000000000000/bui ld/docshell/shistory/src/nsSHEntry.cpp, line 622 Confirmed in Nightly 2014-01-17-mozilla-central-debug build, win 7 x64.

Daniel, could you please help with the right component?

See also bug 645229, another instance of this assertion on a particular testcase. (Can't be sure it's a duplicate, though, so probably best to leave them as separate bugs for now.)

(Reporter: See also https://developer.mozilla.org/en-US/docs/Debugging_Mozilla_on_Windows_FAQ#Disabling_ASSERTIONS if this is causing you trouble.)

I can reproduce this in a debug build of up-to-date (as of yesterday) mozilla-central, on 64-bit Linux.

this does no longer occur as of today for me on windows 7 64bit can you still reproduce on 64 bit linux?

Yes, I still see this in 64 bit linux. (using a debug build from today using cset 9e63d3c61e5b, on mozilla-inbound, which is just awaiting merging to mozilla-central) So, no change as far as I can tell.

I have issue about seamonkey-2.33.1/work/comm-release/mozilla/docshell/shistory/src/nsSHEntry.cpp, line 651 I was browsing http://mbe.oxfordjournals.org . JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/fingerprint.js, line 62: ReferenceError: reference to undefined property navigator.cpuClass JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 18: ReferenceError: reference to undefined property d.traditional JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 18: ReferenceError: reference to undefined property f.ajaxSettings.traditional JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 17: ReferenceError: reference to undefined property c[0] JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 17: ReferenceError: reference to undefined property a[d] JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 18: ReferenceError: reference to undefined property h[j] JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property a.selector JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property a.nodeType JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/pages/hw-content.js, line 1342: ReferenceError: assignment to undeclared variable flag JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property a[f.expando] JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property a[f.expando] JavaScript strict warning: http://mbe.oxfordjournals.org/publisher/js/hw-publisher-article-dynamic-elements.js, line 13: ReferenceError: assignment to undeclared variable liElement JavaScript strict warning: http://mbe.oxfordjournals.org/publisher/js/hw-publisher-article-dynamic-elements.js, line 14: ReferenceError: assignment to undeclared variable aElement JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property a[0] JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property f.event.triggered [2313] WARNING: blocked access to response header: file /var/tmp/portage/www-client/seamonkey-2.33.1/work/comm-release/mozilla/dom/base/nsXMLHttpRequest.cpp, line 1261 JavaScript strict warning: http://mbe.oxfordjournals.org/shared/js/jquery-min.js, line 16: ReferenceError: reference to undefined property f[0] ^G[2313] ###!!! ASSERTION: Adding a child where we already have a child? This may misbehave: 'Error', file /var/tmp/portage/www-client/seamonkey-2.33.1/work/comm-release/mozilla/docshell/shistory/src/nsSHEntry.cpp, line 651 ^G[2313] ###!!! ASSERTION: Adding a child where we already have a child? This may misbehave: 'Error', file /var/tmp/portage/www-client/seamonkey-2.33.1/work/comm-release/mozilla/docshell/shistory/src/nsSHEntry.cpp, line 651 For application/pdf found plugin npwrapper.nppdf.so