Java bad version number in. class file

Error message:

Java.lang. unsupportedclassversionerror: Bad version number in . class file
At Java.lang.ClassLoader.defineClass1 (Native Method)
At Java.lang.ClassLoader.defineClass (Unknown Source)
At Java.security.SecureClassLoader.defineClass (Unknown Source)
At Java.net.URLClassLoader.defineClass (Unknown Source)
At java.net.urlclassloader.access$100 (Unknown Source)
At Java.net.urlclassloader$1.run (Unknown Source)
At java.security.AccessController.doPrivileged (Native Method)
At Java.net.URLClassLoader.findClass (Unknown Source)
At Java.lang.ClassLoader.loadClass (Unknown Source)
At Sun.misc.launcher$appclassloader.loadclass (Unknown Source)
At Java.lang.ClassLoader.loadClass (Unknown Source)
At Java.lang.ClassLoader.loadClassInternal (Unknown Source)
Exception in thread "main"

This problem occurs, usually due to the low compile level and run environment (JRE) versions of the project.

Workaround: Adjust the version of the project's compile level and run environment (JRE).

Java bad version number in. class file