Java class file has wrong version 52.0, should be 50.0

I got this error when trying to test the Chilkat Java API straight out of the box..

Test.java:6: cannot access com.chilkatsoft.CkCrypt2
bad class file: comchilkatsoftCkCrypt2.class(comchilkatsoft:CkCrypt2.class)
class file has wrong version 52.0, should be 50.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
import com.chilkatsoft.CkCrypt2;
                      ^
Error: Could not find or load main class Test