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Install Java 8 on the server where Jira is running.
Open <JIRA_HOME>/plugins/activitytimeline/config/at.properties file for editing. <JIRA_HOME> is usually /var/atlassian/application-data/jira on Linux servers.
Add the following line into that fiefile:
Code Block at.java_home.path=JAVA8_EXECUTABLE_PATH
where JAVA8_EXECUTABLE_PATH is full path to installed Java 8 executable file. Examples:
/usr/lib/jvm/jre-1.8.0-openjdk.x86_64/bin/java
/usr/lib/jvm/jre-1.8.0/bin/java
C:\\Program Files\\Java\\jre8\bin\\java.exe
Please note that each back-slash should be doubled for Windows OS based server.
Save at.properties file.
Open a troubleshooting page at the following link and click Restart (or Start) service button: https://<JIRA_HOME_URL>/plugins/servlet/activitytimelineconfig/configuration
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