Error " Unsupported major.minor version " in Java

This error is because from your computer's default jvm (Java Virtual Machine), you are trying to run a class that was compiled into a version of the JDK (Java Development Kit) that is higher than the JVM (for example, trying to run a class compiled into JDK 1.6 with JVM 1.4).

If you want to check the version of the conflicting class, run the Command javap which is the decompiler that comes included in the JDK, running it from %JAVA_HOME%\bin (it is recommended to do it from the latest version of the JDK).

For example, if you want to know in which version of Java the Class MiClase.class is compiled, run the following commands:

1. javap -verbose MiClase.class | findstr "major" which would return something like:

   Major version: 50

2. javap -verbose MiClase.class | findstr "minor" which would return something like:

   Minor version: 0

Thus the equivalences between Java versions and their 'major version' are as follows to date:

Java 1.2 corresponds to major version 46

Java 1.3 corresponds to major version 47

Java 1.4 corresponds to major version 48

Java 5 corresponds to major version 49

Java 6 corresponds to major version 50

Java 7 corresponds to major version 51

Java 8 corresponds to major version 52

(list Source )

This is a simple way to do this check with the javap command, although there are more. If you know them, you are welcome to make your contribution as a comment to this answer.