“ClassFormatError: Incompatible magic value” when trying to run Java jar file

Question

I typed in \"java -jar ShowTime.jar\", and got this error message:

Exception in thread \"main\" java.lang.ClassFormatError: Incompatible magic value 13470932         


        

Answer 1

That usually means that you compiled the jar for a newer version of java than you ran it with. Check to see if you are using the same version of java to compile and run. If that doesn't fix the problem, please provide more info such as the compiler command and the output of java -version.