# Problem with Log4j in Docker image 'universalrobots/ursim\_e-series'

**URL:** <https://forum.universal-robots.com/t/problem-with-log4j-in-docker-image-universalrobots-ursim-e-series/29312>\
**Category:** Java\
**Created:** [June 30, 2023, 1:18pm UTC](https://forum.universal-robots.com/t/problem-with-log4j-in-docker-image-universalrobots-ursim-e-series/29312 "2023-06-30T13:18:13Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![lwh](https://avatars.discourse-cdn.com/v4/letter/l/779978/32.png) [@lwh](https://forum.universal-robots.com/u/lwh)\
**Post date:** [June 30, 2023, 1:18pm UTC](https://forum.universal-robots.com/t/problem-with-log4j-in-docker-image-universalrobots-ursim-e-series/29312/1 "2023-06-30T13:18:13Z")

</div>

When I run the simulator docker image ([https://hub.docker.com/r/universalrobots/ursim\_e-series](https://hub.docker.com/r/universalrobots/ursim_e-series)) it reports missing Log4j files:

ERROR StatusLogger Log4j2 could not find a logging implementation. Please add log4j-core to the classpath. Using SimpleLogger to log to the console…

I can see there are multiple logging related files in the docker image, but apparently they are somehow not in the classpath:

/ursim/GUI/bundle/polyscope-java-logger-impl-1.2.88.jar  
/ursim/GUI/bundle/polyscope-logging-impl-7.10.32.jar  
/ursim/GUI/bundle/log4j-core-2.17.1.jar  
/ursim/GUI/bundle/log4j-api-2.17.1.jar  
/ursim/GUI/bundle/polyscope-logging-api-7.10.32.jar  
/ursim/GUI/bundle/polyscope-java-logger-api-1.2.88.jar  
/ursim/GUI/bundle/commons-logging-1.2.jar  
/ursim/GUI/bundle/polyscope-logging-driver-7.10.32.jar

That is probably why my “LOGGER.warn” messages are not printed (whereas System.out.println is printed).

Please advice how I can enable Log4j?