I am Sonarqube, using version 9 and java version 11. Ubuntu server where sonarqube is installed .I get the error in the picture while scanning the database project.
java.lang.UnsupportedClassVersionError: org/sonar/batch/bootstrapper/EnvironmentInformation has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
Even though the server is using Java 11, it looks like you may be running the scanner client with an older version of Java. Can you make sure Java 11 is the JDK used on the system where you are scanning?
You will see a log entry very early in the scan output that indicates what version of Java the scanner is using:
As you see, your scanner is using Java 8. If you have not already, you need to install Java 11 on this host. If you have, and you require JDK 8 on this machine for some reason, you’ll need to set JDK_HOME to the path to the JDK 11 install. You can find more details in our documentation.