# Java version issue? **URL:** \ **Category:** Graylog Central (peer support)\ **Created:** [June 13, 2023, 11:39pm UTC](https://community.graylog.org/t/java-version-issue/29152 "2023-06-13T23:39:14Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![grace2023](https://avatars.discourse-cdn.com/v4/letter/g/da6949/32.png) [@grace2023](https://community.graylog.org/u/grace2023)\ **Post date:** [June 13, 2023, 11:39pm UTC](https://community.graylog.org/t/java-version-issue/29152/1 "2023-06-13T23:39:14Z")
Before you post: Your responses to these questions will help the community help you. Please complete this template if you’re asking a support question. **Don’t forget to select tags to help index your topic!** **1. Describe your incident:** After upgrading Graylog-server to version 5.0.2 using yum, graylog service will not start, the /varlog/messages shows the following error message: Exception in thread “main” java.lang.UnsupportedClassVersionError: org/graylog2/bootstrap/Main has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 52.0 **2. Describe your environment:** - OS Information: RHEL 8.8 - Package Version: 5.0.2 - Service logs, configurations, and environment variables: Error: A JNI error has occurred, please check your installation and try again Jun 13 17:22:04 graylogdev1 graylog-server[8611]: Exception in thread “main” java.lang.UnsupportedClassVersionError: org/graylog2/bootstrap/Main has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 52.0 **3. What steps have you already taken to try and solve the problem?** Tried upgrading the java packages, but this did not fix the issue. I tried upgrading to \*\*OpenJDK 17 as this is supposed to handle class file version 61.0, from what I read. **4. How can the community help?** Help point me to a resolution for this issue. **Helpful Posting Tips:** [Tips for Posting Questions that Get Answers](https://community.graylog.org/t/tips-for-posting-questions-that-get-answers/21828) [Hold down CTRL and link on link to open tips documents in a separate tab] ---
**Author:** ![Marvin1](https://avatars.discourse-cdn.com/v4/letter/m/ecb155/32.png) [@Marvin1](https://community.graylog.org/u/Marvin1)\ **Post date:** [June 14, 2023, 2:49pm UTC](https://community.graylog.org/t/java-version-issue/29152/2 "2023-06-14T14:49:32Z")
Hey, did you set the new java as the JAVA\_HOME? Greetings Marvin ---
**Author:** ![drewmiranda-gl](https://sea2.discourse-cdn.com/flex016/user_avatar/community.graylog.org/drewmiranda-gl/32/13376_2.png) [@drewmiranda-gl](https://community.graylog.org/u/drewmiranda-gl)\ **Post date:** [June 14, 2023, 5:05pm UTC](https://community.graylog.org/t/java-version-issue/29152/3 "2023-06-14T17:05:23Z")
Can you try to “comment out” (add a `#` to the line) this line, `JAVA=/usr/bin/java`, in your [JVM settings](https://go2docs.graylog.org/5-0/setting_up_graylog/default_file_locations.html) file? Should be `/etc/sysconfig/graylog-server` for RPM/yum installs. Should look like this when commented out ![image](https://us1.discourse-cdn.com/flex016/uploads/graylog/original/2X/1/14a3ac27f004756a8e433929381d9879e47ce3ef.png) This will allow graylog to use its bundled JDK and no longer rely on the OS jdk. ---
**Author:** ![grace2023](https://avatars.discourse-cdn.com/v4/letter/g/da6949/32.png) [@grace2023](https://community.graylog.org/u/grace2023)\ **Post date:** [June 14, 2023, 5:36pm UTC](https://community.graylog.org/t/java-version-issue/29152/4 "2023-06-14T17:36:19Z")
> [@drewmiranda-gl](#): > > ine, `JAV` ## @drewmiranda-gl Thank you, I did as you instructed and then got the error message in the logs that says this: graylog-server[5230]: Unrecognized VM option ‘UseConcMarkSweepGC’ Jun 14 11:30:10 graylog-server[5230]: Error: Could not create the Java Virtual Machine. Jun 14 11:30:10 graylog-server[5230]: Error: A fatal exception has occurred. Program will exit. Jun 14 11:30:10 systemd[1]: graylog-server.service: Main process exited, code=exited, status=1/FAILURE Jun 14 11:30:10 systemd[1]: graylog-server.service: Failed with result ‘exit-code’. So I then re-edited the /etc/sysconfig/graylog-server file and also commented out the setting below: #GRAYLOG\_SERVER\_JAVA\_OPTS=“-Xms2g -Xmx2g -XX:NewRatio=1 -server -XX:+ResizeTLAB -XX:+UseConcMarkSweepGC -Dlog4j2.formatMsgNoLookups=true -XX:+CMSConcurrentMTEnabled -XX:+CMSClassUnloadingEnabled -XX:-OmitStackTraceInFastThrow” I saved and quit the file and the started graylog-server service and that all fixed the issue. Will I have any problems moving forward with commenting out the above setting for GRAYLOG\_SERVER\_JAVA\_OPTS? Thanks again for taking the time to help me out. ---
**Author:** ![drewmiranda-gl](https://sea2.discourse-cdn.com/flex016/user_avatar/community.graylog.org/drewmiranda-gl/32/13376_2.png) [@drewmiranda-gl](https://community.graylog.org/u/drewmiranda-gl)\ **Post date:** [June 14, 2023, 6:42pm UTC](https://community.graylog.org/t/java-version-issue/29152/5 "2023-06-14T18:42:30Z")
I recommend replacing that line with the updated defaults from [fpm-recipes/recipes/graylog-server/files/environment at 5.0 · Graylog2/fpm-recipes · GitHub](https://github.com/Graylog2/fpm-recipes/blob/5.0/recipes/graylog-server/files/environment) ```auto GRAYLOG_SERVER_JAVA_OPTS="-Xms1g -Xmx1g -server -XX:+UseG1GC -XX:-OmitStackTraceInFastThrow" ``` Change `-Xms1g` and `-Xmx1g` to another value if you need more heap space for graylog-server. Typically 1g is sufficient but in some scenarios with higher log throughput (message per second) 2g is needed to avoid random JVM out of memory crashes. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/graylog/original/3X/c/7/c7c09c6b5099570133d6502b83f50ba4430de5b6.png) [@system](https://community.graylog.org/u/system)\ **Post date:** [June 28, 2023, 6:43pm UTC](https://community.graylog.org/t/java-version-issue/29152/6 "2023-06-28T18:43:11Z")
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