Mutation score is always 100

[shoryacr7]

Mujava generates the correct mutants but on executing the mutants, the mutation score is always 100. The same program was executed with a different mutation tool and the same test file, which resulted in a more practical score, thus validating the test file correctness.
Attached screenshot shows that although all the test cases pass for a mutant, i.e. the mutant is not killed, the mutation score is always 100 (example- COD_1). The same result was achieved with all the different programs executed with Mujava.
Can you state the problem if any, or a way to resolve this issue.

[winonecheng]

See Q2 of FAQ in wiki.
Remove directory $MuJava_HOME\classes in classpath.