Cgoban problems and solutions

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New versions of software bring new problems (remember Murphy!).

This is not a bug page!

Please email bugs to admin of

This page is dedicated to work-arounds for problems (or difficulties) with CGoban3.
Work-arounds for problems and difficulties with the old version may also be collected on this page.
You may also present problems (and difficulties) without presenting the solution (because you don't have).

See also ...

See also KGS Related Utilities.
See also KGS Wishlist / File Handling.
See also KGSBugs.
See also KGSAudio.
See also [ext] KGS-FAQ, (troubleshooting section)
See also [ext], mostly in french, but with a Google-trick[1] you can read a rough translation to (as minimum) englisch.

Table of contents

Solutions for CGoban 3.x (for new KGS-server)

CGoban 3.5.22 doesn't start

You need Java 8 to run the .jar file (this is, what I do). I never use the webstart file, instead, in a terminal/cmd-window, I run PATH_TO_MY/java -jar cgoban.jar (just make a desktop starter for this). RueLue

KGS 3.5.22: KGS games archive was broken

The archive is back.

Update needed

(and you must be online) every time you use CGoban3 (Problem with webstarter and your computer / configuration):
Look for a file 'RMcgoban.jar' on your harddisk. It can be in a folder like:
c:\documents and settings\your-user-name\applicationdata\Sun\Java\Deployment\cache\javaws\http\\P80\DMjavaBin\
Using win98, i found the file in a win-subdirectory: c:\win-dir\Application Data\sun\java\...
This 'RMcgoban.jar' is the (by webstarter) last updated file of what you formerly used as CGoban (CGoban.jar was the file started by CGoban.exe).
This RMcgoban.jar can be started directly, when jar-files are associated with the Java runtime environment. There is another way for starting CGoban directly by starting Java with arguments and (pathto/)CGoban from command line or with desktop-link. You need to check out yourself, how to make this work.
RueLue: with Linux you can open a command shell in the directory, where your RMcgoban.jar file is. Type in java -jar RMcgoban.jar

CGoban for Java Web Start don't start

This might be caused by a clash of javaws and firewall, one workaround is parameter -Xnosplash, e.g.: javaws.exe -Xnosplash [ext] Other solutions can be found at: [ext]

Another possibility, if using the OpenJDK under Linux, is to ensure that the 'rhino' JavaScript implementation is installed. This can prevent a hang at the IcedTea? window on some linux systems using OpenJDK and IcedTea? for webstart.

How to run Cgoban 3 in Ubuntu Hardy Heron

  • Keep in mind that Hardy is shiny, new and still in development
  • Here's the command:
LIBXCB_ALLOW_SLOPPY_LOCK=true padsp javaws [ext]
  • padsp is for pulseaudio to pretend to be /dev/dsp
  • LIBXCB_ALLOW_SLOPPY_LOCK=true is to avoid a problem with Java and X
  • javaws [ext] is for running Cgoban3, and updating the client if there's a new one ready
  • "update-java-alternatives" can be used to set Sun's Java as the default, if it isn't already. Make sure you use the "javaws" that belongs to Sun's Java, since Cgoban3 doesn't work otherwise, last time I checked. Luckily, Java is open source now. Just give it a year or two and it will be superb on Linux! :)

meuns? My javaws can't load cgoban.jnlp on my hardy heron. [ext]

How to get javaws in 64-bit Ubuntu Linux

Java Web Start is required by the KGS client. Sun doesn't provide javaws in 64-bit Java yet. If you have a 64-bit Linux installation, a workaround is to install 32-bit Java and use its javaws. See: DEADLINK

This link in works:


edit: I am suspecting the above information to be old and wrong. 64-bit Debian has a javaws in sun-java6-jre package, so I am suspecting it to be in 64-bit Ubuntu as well.

Running the cgoban.jar file directly

It's possible to deduce the name of the .jar file in the .jnlp file, download it and run it. Currently the jar files can be found at:

[ext] (no file association version)

Then go with:

java -jar cgoban.jar


Using Ubuntu 16.04 in jan-2021, java web start is obsolete.

I couldn't make the current cgoban jar (version 3.5.23) work with any openjdk version, well the jar executed but couldn't actually play a game, because the client wouldn't admit my mouse clicks. Solved it by installing bellsoft's java11 jdk. I suspect any pure java runtime will work.

1. Install bellsoft's java11 jdk.

2. Download [ext]

3. Copy cgoban.jar to /opt/kgs/

4. chmod 755 /opt/kgs/cgoban.jar

5. Execute:

/usr/lib/jvm/bellsoft-java11-amd64/bin/java -jar /opt/kgs/cgoban.jar

That's it. Happy gaming!

Connection Problems with IPv6 and Sun Java Version 6 in Debian

You can get connection errors if you are using sun-java6 java package in Debian squeeze. Employing one of the workarounds in the following bug reports will hopefully resolve your connection issues:


How to fix broken window resizing in Linux

See [ext] which talks specifically about CGOBAN's problem with resizing windows for some users. It suggests getting rid of Beryl if you use it, and/or modifying /etc/environment to have:

export AWT_TOOLKIT=MToolkit

Unfortunately since MToolKit?+Java has a serious bug on amd64 linux, this might not work for you if you are on 64bit. The following solution will slow down your window's refreshing, but it is another workaround I found: Run the java program with the

-Dswing.handleTopLevelPaint=false parameter.

Cgoban doesn't get your timezone right in Linux

For some reason on my Ubuntu system, Cgoban did not recognize my time zone even though it's set correctly on my computer. All times showed up as GMT. Switching from America/Detroit to America/New_York solved the problem. They're both in the US Eastern time zone, so it doesn't matter (except I think for dates prior to 1915 or something), so it's a good workaround. If you have the same problem, selecting a different city in your time zone may do the trick. - Fwiffo

File association

If you're having trouble try KGS CGoban File Association.

Sgf-files saved by the old server version

contain some problems. Those files didn't become converted (not yet? 30.9.06). See the section on the old version of CGoban below.

Buddy lists

as they were used in CGoban2 do not show up in CGoban3, because the latter expects them on the server rather than on your harddisk. The upgrade didn`t migrate the lists automatically. You can, however, try to find the old buddy or censored lists and manually enter the nicknames into CGoban3, one by one.

On linux, a good place to check is ~/.java/.userPrefs/org/igoweb/cgoban or similar. With some luck, you can find two cryptically named directories there, containing one xml file each. One contains your buddy nicks, the other the censored ones.

On Windows, you need to dive into the registry. This is potentially harmful to your system, so it`s recommended to backup the registry first. (I know, the following isn`t really comprehensible to people new to registry editing yet. Please, improve it as you see fit. I don`t have windows at hand right now.) Whilst some freeware registry editors like reghance by Lavasoft are more convenient to deal with, regedit.exe (which comes with windows) also suffices. Search for any buddy name you remember. Once you`ve found an occurrence, check if all the other buddies are mentioned nearby, too. If that`s not the case, you probably haven`t found the buddylist yet, so search on. Otherwise just export the key containing those names to buddies.txt (do not use the default .reg extension). Make sure you don`t alter anything in the registry unless you know what you are doing. Close the registry editor, navigate to buddies.txt and open it. There you are.

Copy file to disk

(from some user's info, file list) starts every time in 'My Documents' (CGoban 3.3.13, Java 1.5.0_09-b01, XP-SP2) (and w98, CGoban 3.3.13, Java 1.6...), I hope, this will be fixed in one of the next versions. Work-around (like editing a config file)?
Same with CGoban 3.3.16, Java 1.6..., Win98 and XP-SP2.
(Not really) workaround: put a link to your desired folder in the 'My Documents'-folder. CGoban resp. Java follows the link. (Suitable for a small amount of game files.)


Help - my computer freezes every time I try to play on-line or view saved files (W.98SE, Java 1.5.0_07, Cgoban 3.3.8) - at any point from start to end of game.

Update - Not Java or Cgoban - video driver at fault... the latest version cured this :-) Note - SET J2D_D3D=false did not work

Help click (by menu or button) without response

Click for help (menu or button) and nothing happens. I remember, one time, help came up and, before this, my browser (Firefox) gave me a note of a suppressed popup. But popups for are allowed now and I tried unchecking 'block popups', but no help.

At the moment (aug.'2012, and since some jears) cgoban.jar cannot give urls to the system (other Java programs can!). Possibly this is the price for an actual Java version. Start CGoban by the .jnlp file and the links will work.

Try running the Java thingy - javacpl.exe & 'Advanced' tab - lots of choices - something may work :-)

It's same as javaws - settings, advanced; glue gave me the hint of starting javaws.exe (Java Web Start) alone and look around in the settings - no, nothing found in the settings. But I tried something, what helped: I started javaws alone (as in glue's hint, javaws is in the win path), and deleted CGoban from the executables list, closed javaws and started the cgoban-nfa.jnlp-file once more. This made a new download of the cgoban-files and now help worked (with win-xp); same with win-98 was no success (vers.3.3.9: same). Now and with 3.3.16 no problem.

When I click for help in jnlp-client (button or menue), instead of browser with help page only notepad opens and complains 'Syntax for file name, directory or volume (german 'Datentraeger') is wrong'. cgoban 3.3.16, w-xp-sp2, java 1.6
I tried:

  • uninstall all versions of (sun)java + deleted the remaining cache directories (and reinstall)
  • searched in registry for apparently wrong assignment (nothing found)
  • fetched new jnlp-file from kgs

With Jin-chess (also java-prog.) no problem; same with help click from browser-kgs: it's all fine; same with another user on same machine and jnlp-kgs: no problem. I know, where the help is on gokgs, that's not the problem, but i need it called directly from the client. Is there someone out there, who knows the solution? Thanks for solution! RueLue

Now is version 3.3.17 and first, nothing happened with help click, Then, after javaws -uninstall (is sun-java) and new start of jnlp-file, it is like before: notepad opens. uuuuhhhh! RueLue

New Help System for KGS

March'07: Click on HELP inside CGoban sends me to a file at gokgs: Sorry, this help page hasn't been written yet. (It is the main help file: [ext]
April '07: They are working on it. There are editor's / translator's links on the page. If you think, you can translate from english to your first language and want to help writing the help pages, read [ext] .
They are working on a new help system (context sensitive). If help is not yet on your national language page, call the english version of the page (the link hides below the toc under the US-flag). You can find the help-pages for Cgoban/KGS at [ext] .

Where to find the CGoban archive

The old Java version (5 = 1.5) used as archive name RMcgoban.jar and the folder:
(XP) c:\documents and settings\your-user-name\applicationdata\Sun\Java\Deployment\cache\javaws\http\\P80\DMjavaBin\
The new Java version (6 = 1.6) uses a new cryptic code as name for the CGoban archive (on my machine, Win98, it is 3f4b305c-3faea52b without extension). I found it in
(win98) C:\WINDOWS\Anwendungsdaten\Sun\Java\Deployment\CACHE\6.0\28\
o.k. - with XP and Java 1.6 (=6) it is in folder C:\documents and settings\your-user-name\applicationdata\Sun\Java\Deployment\cache\6.0\28\ with a cryptic code (on my machine = 3f4b305c-1493a3c3) as name without extension. You can copy this file to a folder of your choice, rename it as you like (under Win maybe good to give extension '.jar') and start it.
When you don't get the connection because of error 'Socket is not connected: connect' , you make a link to the file in the above mentioned folder and change the link to
'javaw.exe -jar ...(original_path_and_name_of_archive)' .

How to use CGoban3 as a browser helper app

Anonymous: How do you set up CGoban3 as a browser helper app to open SGF files? The older CGoban2 took a filename on the command line, so the setup was obvious. The new CGoban3's command line begins with 'javaws' and it is not clear how to get a filename passed into the app code.

Phelan: I'm not sure if you want something different, but have you seen File Association above, in this page? I got file association version, and when I click a SGF link, it asks me if I want to save the file, or open in CGoban(more accurately, the application name that appears is "Java Web Start Launcher".

Clam: Same issue - some clarification. I have cgoban3 installed and working. I can open and edit SGF files Ok if i select the sgf within cgoban3. The file association does NOT work if i double click an SGF file in windows. If I go to any senseis page and click a SGF image it pops up "You have chosen to open Blah.sgf which is a : Jago from [ext]". The option is to open with 'javaws.exe'. But doing so launches Java which fails with an error. I once installed and uninstalled Jago. I have gone into Windows list of file associations and deleted the SGF entry. Still no joy. Any other suggestions ?

dpc . wikidot . com: Download [ext] and use it instead like that:

java -jar /path/to/file/cgoban.jar -edit <file>
On linux you can make shell script:

java -jar /path/to/file/cgoban.jar -edit $*

on windows try creating similar *.bat. Then associate sgf files with your script and everything should be working. If in doubt contact me using my nick as an url.

Nick?: On Mac create an App using the Automator is easiest.

  1. Open Automator
  2. choose "application"
  3. from library add "run shell script"
  4. add the line "java -jar /path/to/file/cgoban.jar -edit $@"
  5. save the application as
  6. in browser choose as default for .sgf files

CGoban vs ClearType

[ext] (read about ClearType in Wikipedia)

uXs: I use ClearType on my PC because I think it improves how fonts look on my PC. (You can disagree but this isn't the place for that.) Unfortunately, ClearType messes up the fonts in CGoban, making them look horrible. Does anyone know a way to fix this? Turning ClearType off for everything is not an option.

uXs: Found a solution. You need to explicitly download the cgoban.jnlp webstart file and edit it, setting the property "apple.awt.textantialiasing" to "off". Also add another property "awt.useSystemAAFontSettings" and set it to off as well. This disables all font AA in Cgoban.

eng60340 : edited the cgoban.jnlp file. it works. but if i launch kgs via cgoban icon, cleartype screws up again. how do i edit the setting so that the cleartype issue can be resolve permanently ?

Anonymous : Set the cgoban icon launch "java -Dapple.awt.textantialiasing=off -jar cgoban.jar" (java must be in the executable path)

Ubuntu 10.4, Gnome (Linux): CGoban shows black stones in pink

RueLue, 3.4.14: I use CGoban since years and now (in Windows and now also often in Linux. Suddenly, after logging in (in Ubuntu, Gnome (Linux)), the black stones are shown in pink (magenta). When i open a board locally, before I log in, it is shown normal, but switches partly to pink, as soon as I am logged in: [ext] example (the black stones shown black are played before I logged in). Switching textures off shows the stones black (and white) as they should be - without textures.

Solution: I used the bugfix (in the file menu) - ok-ok, I stepped into the fools' trap. Was good! Thankyou! RueLue

Ubuntu 10.4, Gnome (Linux): CGoban shows artifacts (solved)

RueLue, 3.4.14: This is a behaviour, I observe since I use Ubuntu 10.4 regularly: The board shows artifacts in green (same structure as the CGoban background) ([ext] example)

Solution: minimize the board window and resize it. The artifacts should be gone.

Some sounds missing

Since some months some important sounds in CGoban are missing. To work around this without an outdated Java version, you need to start CGoban with a Java option: -D<name>=<value>
This sets a system property, here: sun.sound.useNewAudioEngine
apparently this is from on set to true
so you start CGoban a) directly:

java -Dsun.sound.useNewAudioEngine="false" -jar [PATH/TO/YOUR/]cgoban.jar

or (in Windows)

javaw -Dsun.sound.useNewAudioEngine="false" -jar [PATH\TO\YOUR\]cgoban.jar

seemingly this works only with java 1.6.x (I tested this with Java 1.7, but without positive result)

Get the actual CGoban.jar: [ext] (or)... [ext] /cgoban-nfa.jar

There is also a way to start the .jnlp file with this option ("javaws -J <options> ..."). So that should be:

javaws -J-Dsun.sound.useNewAudioEngine="false" [PATH\TO\YOUR\]cgoban.jnlp

I haven't had it running here this way.

cgoban on less-famous window managers

If you use a window manager such as dwm, chances are Java does not know its name, and that you may have trouble with menus or resizing windows.

A workaround is to ask your operating system to lie about which window manager is running. A program that does just that is wmname. Once installed, run (for instance)

wmname LG3D

This will not be a permanent change. wmname is available as a standalone utility in some GNU/Linux distributions, and in the package suckless-tools in debian. (check [ext] for more).

Not possible to save file to disk

In KGS Wishlist/File Handling#toc41 a user wrote (some years ago, ~2012):

  • Currently a guest user can't save a game from another user's game list.

Possible reason:

    • Did you try this with the in-browser-client? There it is (was) never possible to save anything to disk. Use the client, which is started with java -jar CGoban.jar . By the way: currently the in-browser-client is deactivated and will possibly never come back. RueLue

Solutions for CGoban, old version

The circle markers ('cr')

in the sgf-files made by the old server version lead to some difficulties. The discussion was on page KGS Issue - CR Marks on Moves (page gone?) Good would be a little program to delete these from the old kgs-files (folders recursively, check, if saved by kgs, check if game date before..., then ...) Do with Multigo? ( Maybe there is a solution on page SGF Organising Utilities.

Related: [ext]

The territory marking in the sgf-files

made by the old server version lead to some difficulties with other programs:
there is a tag hided 'KGSDE' in all files which ended with scoring. It marks all prisoner stones, which were still on the board at end of game. That is a killer for some other viewers / editors (Drago, older version; the new version, 2.20, eats those files without problems). (Script-solution? Do with Multigo?) Maybe there is a solution on page SGF Organising Utilities.
O.K. - if there is no other program with this problem, this could be obsolete. Rue.
I searched a bit and found this: ; [ext] has it archived. I assume the programming language is [ext] Pike. Rue.
For some problems with SGF see: [ext] - Section 4.2. ; it tells: update your viewer, if it is older than one year.


(Was about ... See also KGS Related Utilities.)
Ruedi from Luebeck: I think, the content of this page belongs there. I will merge.
blubb: Huh? I don`t quite think so. In my view, the utilities page neither does nor should cover verbal hints or tricks as provided here. It`s just about the tools available.
Phelan: I agree with blubb, that page should be about the utilities, as not all the utilities are about KGS problems, nor solutions to them, just expansions.
Ruedi from Luebeck: Yes, right. I read '... workarounds ...' and 'KGS Related Utilities' and my fingers were fast. So I let it as it is.


[1] A trick to get a rough translation of some pages to english (or other languages)
Enter a typical phrase (enclosed with double quotes) or the adress of the desired page into the search line of google. Most times google will list that page in the search results and (with luck) will offer to translate it. You can follow the links on the translated page: they are also translated.

[ext] found by google
The live transmission FAQ for KGS, written in french by glue of KGS:
[ext] Scribe How To links to a google search for glue's french HowTo page.
Translate this page:
[ext] Cgoban problems and solutions links to a google search for this page
Note: This way (copy phrase and paste in google) you can also translate Japanese, Korean and Chinese pages!

Extensive about this topic: How to translate Sensei's

hth RueLue

Cgoban problems and solutions last edited by Dieter on November 29, 2023 - 13:40
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