Can somebody help me for the error in Java?

Question

I have just installed Java and java program compiles with no error in CMD,
(javac [className], gives no error)

But while executing it says:

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: JVMCFRE003 bad major version; class=Firsttest, offset=6
at java.lang.ClassLoader.defineClassImpl(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:346)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:154)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:729)
at java.net.URLClassLoader.access$400(URLClassLoader.java:95)
at java.net.URLClassLoader$ClassFinder.run(URLClassLoader.java:1184)
at java.security.AccessController.doPrivileged(AccessController.java:686)
at java.net.URLClassLoader.findClass(URLClassLoader.java:604)
at java.lang.ClassLoader.loadClassHelper(ClassLoader.java:850)
at java.lang.ClassLoader.loadClass(ClassLoader.java:829)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:325)
at java.lang.ClassLoader.loadClass(ClassLoader.java:809)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:507)

Please help, will appreciate.
I did some YouTube search but still could t fix.
(I use windows 10 64bit)

Answer 1

Do u using javafx swing ..... Awt i guess. i think u using these libraries without setup

Answer 2

Hope these may helps...

https://stackoverflow.com/questions/52671412/error-a-jni-error-has-occurred-please-check-your-installation-and-try-again

https://www.javaprogramto.com/2020/03/java-lang-unsupportedclassversion.html?m=1

Answer 3

@Martin Taylor
In C:\Program Files\Java
its says jdk 17.0.1