# No X11 DISPLAY variable was set, but this program performed an operation which requires it **URL:** \ **Category:** Integrations\ **Tags:** integrations, katalon-studio\ **Created:** [December 14, 2018, 10:50am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496 "2018-12-14T10:50:52Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Shashi1](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Shashi1](https://forum.katalon.com/u/Shashi1)\ **Post date:** [December 14, 2018, 10:50am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/1 "2018-12-14T10:50:52Z")
Hi, While running the test on redhat linux box then getting below error message and script execution is failing. Reason: java.awt.HeadlessException: **No X11 DISPLAY variable was set, but this program performed an operation which requires it**. at org.sikuli.api.robot.desktop.AWTDesktop.(AWTDesktop.java:27) at org.sikuli.api.robot.desktop.DesktopScreen.getSize(DesktopScreen.java:43) at org.sikuli.api.AbstractScreenRegion.(AbstractScreenRegion.java:19) at org.sikuli.api.DefaultScreenRegion.(DefaultScreenRegion.java:37) at org.sikuli.api.DesktopScreenRegion.(DesktopScreenRegion.java:11) at com.kms.katalon.core.webui.common.ScreenUtil.(ScreenUtil.java:26) **I tried to set DISPLAY (export DISPLAY=:0.0 or export DISPLAY=:0) value also then below error message is coming** - Reason: **java.awt.AWTError: Can’t connect to X11 window server using ‘:0’ as the value of the DISPLAY variable.** at org.sikuli.api.robot.desktop.AWTDesktop.(AWTDesktop.java:26) at org.sikuli.api.robot.desktop.DesktopScreen.getSize(DesktopScreen.java:43) at org.sikuli.api.AbstractScreenRegion.(AbstractScreenRegion.java:19) at org.sikuli.api.DefaultScreenRegion.(DefaultScreenRegion.java:37) at org.sikuli.api.DesktopScreenRegion.(DesktopScreenRegion.java:11) at com.kms.katalon.core.webui.common.ScreenUtil.(ScreenUtil.java:26) **Can someone please help?** ---
**Author:** ![devalex88](https://dub1.discourse-cdn.com/katalon/user_avatar/forum.katalon.com/devalex88/32/336_2.png) [@devalex88](https://forum.katalon.com/u/devalex88)\ **Post date:** [December 14, 2018, 1:48pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/2 "2018-12-14T13:48:11Z")
Are you setting up the execution yourself, or using the Katalon Docker image? ---
**Author:** ![Shashi1](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Shashi1](https://forum.katalon.com/u/Shashi1)\ **Post date:** [December 14, 2018, 2:01pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/3 "2018-12-14T14:01:27Z")
I am simply running command on redhat Linux 7 box on Chrome headless browser. Not using docker. ---
**Author:** ![devalex88](https://dub1.discourse-cdn.com/katalon/user_avatar/forum.katalon.com/devalex88/32/336_2.png) [@devalex88](https://forum.katalon.com/u/devalex88)\ **Post date:** [December 14, 2018, 2:13pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/4 "2018-12-14T14:13:11Z")
As far as I know Sikuli requires a desktop to work correctly. One option is to execute the tests with normal Chrome and Xvfb. You can take a look at this script as an example: > ---
**Author:** ![Shashi1](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Shashi1](https://forum.katalon.com/u/Shashi1)\ **Post date:** [December 15, 2018, 2:59am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/5 "2018-12-15T02:59:49Z")
Can someone please help on this? ---
**Author:** ![Timo\_Kuisma](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@Timo\_Kuisma](https://forum.katalon.com/u/Timo_Kuisma)\ **Post date:** [December 15, 2018, 10:48am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/6 "2018-12-15T10:48:43Z")
Hi, are you set your display as DISPLAY=:1 this is needed that cause X11 programs need to know where to display windows ---
**Author:** ![Shashi1](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Shashi1](https://forum.katalon.com/u/Shashi1)\ **Post date:** [December 17, 2018, 5:24am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/7 "2018-12-17T05:24:51Z")
Yes. I tried but getting below error message - **java.awt.AWTError: Can’t connect to X11 window server using ‘:1’ as the value of the DISPLAY variable.** ---
**Author:** ![devalex88](https://dub1.discourse-cdn.com/katalon/user_avatar/forum.katalon.com/devalex88/32/336_2.png) [@devalex88](https://forum.katalon.com/u/devalex88)\ **Post date:** [December 17, 2018, 8:46am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/8 "2018-12-17T08:46:30Z")
Could you please try using `xvfb-run` to create a virtual display (as shown in my previous answer)? For example, `xvfb-run -s "-screen 0 1024x768x24" ""`. ---
**Author:** ![Timo\_Kuisma2](https://avatars.discourse-cdn.com/v4/letter/t/45deac/32.png) [@Timo\_Kuisma2](https://forum.katalon.com/u/Timo_Kuisma2)\ **Post date:** [December 18, 2018, 5:14am UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/9 "2018-12-18T05:14:53Z")
hi, is it your X started and runs ok? ---
**Author:** ![Shashi1](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Shashi1](https://forum.katalon.com/u/Shashi1)\ **Post date:** [December 22, 2018, 3:53pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/10 "2018-12-22T15:53:14Z")
How I can check? Can you please tell me the command? ---
**Author:** ![Timo\_Kuisma](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@Timo\_Kuisma](https://forum.katalon.com/u/Timo_Kuisma)\ **Post date:** [December 22, 2018, 3:57pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/11 "2018-12-22T15:57:02Z")
HI, not sure, try e.g. this way ps -fea | grep x found from the web ```auto X=$( pidof X ) if [${#X} -gt 0] then echo "X has already been started" else /usr/bin/startx fi ``` ---
**Author:** ![velascojonathanxd](https://avatars.discourse-cdn.com/v4/letter/v/2bfe46/32.png) [@velascojonathanxd](https://forum.katalon.com/u/velascojonathanxd)\ **Post date:** [January 9, 2019, 11:53pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/12 "2019-01-09T23:53:02Z")
Hi, are you using custom image? I think so katalon isnt enable to use other user non-root Regards ---
**Author:** ![Vikas\_Lad](https://avatars.discourse-cdn.com/v4/letter/v/85f322/32.png) [@Vikas\_Lad](https://forum.katalon.com/u/Vikas_Lad)\ **Post date:** [January 26, 2019, 3:13pm UTC](https://forum.katalon.com/t/no-x11-display-variable-was-set-but-this-program-performed-an-operation-which-requires-it/15496/13 "2019-01-26T15:13:22Z")
Hi, I am running into this issue. Kindly provide steps to resolve this issue. Thanks and Regards Vikas