I need more information in order to be able to help. Please run NetBeans with the -J-Dorg.netbeans.modules.extbrowser.SystemDefaultBrowser.level=500 switch, try to reproduce the problem, and then attach the log file located in $NETBEANS_HOME/var/log/messages.log to this problem report

sorry, but there are no any error messages in message.log and level is set to 500

part of message.log:
Diagnostic information
Input arguments:
        -Djdk.home=/usr/java/jdk1.6.0_02
        -Dnetbeans.dirs=/usr/local/netbeans-6.0/nb6.0:/usr/local/netbeans-6.0/ide8:/usr/local/netbea
ns-6.0/java1:/usr/local/netbeans-6.0/xml1:/usr/local/netbeans-6.0/apisupport1:/usr/local/netbeans-6.
0/enterprise4:/usr/local/netbeans-6.0/mobility8:/usr/local/netbeans-6.0/profiler2:/usr/local/netbean
s-6.0/ruby1:/usr/local/netbeans-6.0/visualweb1:/usr/local/netbeans-6.0/identity1:/usr/local/netbeans
-6.0/uml4:/usr/local/netbeans-6.0/harness:/usr/local/netbeans-6.0/cnd1:
        -Dnetbeans.home=/usr/local/netbeans-6.0/platform7
        -Dnetbeans.importclass=org.netbeans.upgrade.AutoUpgrade
        -Dnetbeans.accept_license_class=org.netbeans.license.AcceptLicense
        -Xmx136m
        -Dcom.sun.aas.installRoot=/usr/local/glassfish-v2
        -Xss2m
        -Xms32m
        -XX:PermSize=32m
        -XX:MaxPermSize=200m
        -Xverify:none
        -Dorg.netbeans.modules.extbrowser.SystemDefaultBrowser.level=500
        -Dapple.laf.useScreenMenuBar=true
Compiler: HotSpot Client Compiler
Heap memory usage: initial 32,0MB maximum 135,0MB
Non heap memory usage: initial 52,2MB maximum 252,0MB
Garbage collector: Copy (Collections=500 Total time spent=2s)
Garbage collector: MarkSweepCompact (Collections=7 Total time spent=3s)
Classes: loaded=8005 total loaded=8026 unloaded 21

..............


        org.netbeans.modules.extbrowser/1 [1.11.1 200711261600]


...............

Created attachment 54951 [details]
here is my log file

I understand it NB was still failing when you collected the log, right? What Linux distro are you using (and what version)? Thanks!

NB shows error message and i "ok" it .. netbeans tasks does not interrupts ..

from About box:
Product Version: NetBeans IDE 6.0 (Build 200711261600)
Java: 1.6.0_02; Java HotSpot(TM) Client VM 1.6.0_02-b05
System: Linux version 2.6.22.9-1mdvcustom running on i386; UTF-8; ru_RU (nb)
Userdir: /home/cy6ergn0m/.netbeans/6.0

from shell:
cy6ergn0m@localhost ~ $ uname -a
Linux localhost 2.6.22.9-1mdvcustom #1 SMP Thu Nov 15 12:42:50 MSK 2007 i686 AMD Turion(tm) 64 X2 Mobile Technology
TL-52 GNU/Linux

cy6ergn0m@localhost ~ $ rpm -qi glibc
Name        : glibc                        Relocations: (not relocatable)
Version     : 2.6.1                             Vendor: Mandriva
Release     : 4.1mdv2008.0                  Build Date: Срд 21 Ноя 2007 19:40:13
Install Date: Срд 26 Дек 2007 15:45:26      Build Host: mercury.mandriva.com
Group       : System/Libraries              Source RPM: glibc-2.6.1-4.1mdv2008.0.src.rpm
Size        : 14926572                         License: LGPL
Signature   : DSA/SHA1, Срд 21 Ноя 2007 22:12:56, Key ID 9aa8d0d022458a98
Packager    : Mandriva Security Team <security@mandriva.com>
URL         : http://www.gnu.org/software/libc/
Summary     : The GNU libc libraries
Description : .....

firefox user agent:
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.11) Gecko/20070914 Mandriva/2.0.0.11-1.1mdv2008.0

distro Mandriva Linux 2008 free

In the past i has not any problems with external browser at .. i think something broken in netbeans or system, but i do
not know whats happens .. possible it happens after update firefox or netbeans ..

clean netbeans6 on clean system was work good.

in me system also installed gcj and cacao .. but netbeans runs under Sun's JVM.. is possible some conflicts? 

i can run some tests .. 

Can you try the -J-Dorg.netbeans.modules.extbrowser.level=0 switch instead? The log file should contain lines starting with "FINE 
[org.netbeans.modules.extbrowser]:". Thank you!

thanks2 tslota!

i set -J-Dorg.netbeans.modules.extbrowser.level=0 and now browser launches successfully! :)

but, log does't contains "FINE [org.netbeans.modules.extbrowser]:"..

Hmm..sorry, but problem still .. 

If i run NetBeans from KDE's Konsole - launching works, if from KDE's quck launch - it does not work.

With level=0 and when fails, log does'nt contain "FINE.." or other lines abour extbowser .. only version and option level=0

also i think, problem related with quotes in firefox's arguments. I change -remote "openURL({URL})" to {URL} and now it
works always, but firefox's window not popups.

While playing with extbrowser settings i got an exception 
java.lang.IllegalStateException: Can't dispose InputContext while it's active
	at sun.awt.im.InputContext.dispose(InputContext.java:646)
	at java.awt.Window$1DisposeAction.run(Window.java:976)
	at java.awt.Window.doDispose(Window.java:985)
	at java.awt.Dialog.doDispose(Dialog.java:1237)
	at java.awt.Window.dispose(Window.java:932)
	at java.awt.Window.disposeImpl(Window.java:942)
	at java.awt.Window$1DisposeAction.run(Window.java:968)
	at java.awt.Window.doDispose(Window.java:985)
	at java.awt.Dialog.doDispose(Dialog.java:1237)
	at java.awt.Window.dispose(Window.java:932)
	at org.netbeans.core.windows.services.NbPresenter$ButtonListener.actionPerformed(NbPresenter.java:1098)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
	at java.awt.Component.processMouseEvent(Component.java:6038)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
	at java.awt.Component.processEvent(Component.java:5803)
	at java.awt.Container.processEvent(Container.java:2058)
	at java.awt.Component.dispatchEventImpl(Component.java:4410)
	at java.awt.Container.dispatchEventImpl(Container.java:2116)
	at java.awt.Component.dispatchEvent(Component.java:4240)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
	at java.awt.Container.dispatchEventImpl(Container.java:2102)
	at java.awt.Window.dispatchEventImpl(Window.java:2429)
	at java.awt.Component.dispatchEvent(Component.java:4240)
[catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:177)
	at java.awt.Dialog$1.run(Dialog.java:1039)
	at java.awt.Dialog$3.run(Dialog.java:1091)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.Dialog.show(Dialog.java:1089)
	at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:834)
	at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:868)
	at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:856)
	at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:104)
	at org.openide.util.Mutex.doEventAccess(Mutex.java:1223)
	at org.openide.util.Mutex.readAccess(Mutex.java:242)
	at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:841)
	at java.awt.Component.show(Component.java:1419)
	at java.awt.Component.setVisible(Component.java:1372)
	at java.awt.Window.setVisible(Window.java:801)
	at java.awt.Dialog.setVisible(Dialog.java:979)
	at org.netbeans.core.ui.options.general.GeneralOptionsPanel.editBrowserButtonActionPerformed(GeneralOptionsPanel.java:255)
	at org.netbeans.core.ui.options.general.GeneralOptionsPanel.access$500(GeneralOptionsPanel.java:63)
	at org.netbeans.core.ui.options.general.GeneralOptionsPanel$4.actionPerformed(GeneralOptionsPanel.java:181)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
	at java.awt.Component.processMouseEvent(Component.java:6038)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
	at java.awt.Component.processEvent(Component.java:5803)
	at java.awt.Container.processEvent(Container.java:2058)
	at java.awt.Component.dispatchEventImpl(Component.java:4410)
	at java.awt.Container.dispatchEventImpl(Container.java:2116)
	at java.awt.Component.dispatchEvent(Component.java:4240)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
	at java.awt.Container.dispatchEventImpl(Container.java:2102)
	at java.awt.Window.dispatchEventImpl(Window.java:2429)
	at java.awt.Component.dispatchEvent(Component.java:4240)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)

after click at "OK" or "Cancel" button in NetBeans "Options" window and now i can't close it, only File->Exit...

If firefox (2.0.0.12) or mozilla (1.7) already started, netbeans can't launch it. 

This problem reproducible in Linux/x86 and Solaris/sparc.  

I apologize for later reply. What is the state of this issue now, is there still the problem?

Yes. Problem still. On my new machine too. On Linux and Solaris. If browser already running, it sometime works. Often
(90%) launching does not work. Problem was found in 6.0 and now still in 6.1 and 6.5m1.

Thanks, please, could you provide the log file? Sorry for later reply again, I'll start to check this more often.

log does not contain any interesting.. its looks like older log that was attached here..
but i found in FF3 log messages in error console like this (both for every attempt):

Error: Unknown remote command.
Source: file:///home/cy6ergn0m/apps/components/nsBrowserContentHandler.js
Line: 387

Error: [Exception... "'Abort' when calling method: [nsICommandLineHandler::handle]"  nsresult: "0x80004004
(NS_ERROR_ABORT)"  location: "<unknown>"  data: no]


I do'nt know what about FF2, on FF2 launching also was failed. On Solaris with old Mozilla, sometime nb says launching
failed, but after few seconds Mozilla runs.

Hm, it could mean that there is a problem to start the FF. Could you start it from command line (without IDE?) with the
same parameters?

/usr/bin/mozilla-firefox -remote "openURL(http://ya.ru)"

works fine from terminal with firefox3.

Hm, it should be same if you used the same command names. Please, did you copy those values from your FF setting, or
could you, check it is really the same way you tried in command line?
You go to Tools | Options.. press Edit.. button next to combo where you pick the browsers, and then select FF to see
what process name and arguments are used. Please, let me know those are the same you tried. Thanks.

Firefox options:

process: /usr/bin/mozilla-firefox
arguments: -remote "openURL({URL})"

i change arguments to "{URL}" and it works on linux and solaris fine with firefox3 and mozilla 1.7 (on Solaris 10)

note: on Solaris 10/Mozilla 1.7 with changed arguments launching works (Mozilla starts), but netbeans shows error message.

Hm, so there could be the workaround, adding those quotes.

So is it now narrowed to the Solaris/Mozilla 1.7  configuration? I.e. the problem of shown error message? What error
message is shown?

Thanks.

The last part seems to be related to the issue #76970. Making duplicate.

*** This issue has been marked as a duplicate of 76970 ***