Spotted in an erroneous bug report. Consider a class:

package circular;
public class I {
} 

which gets compiled into ./circular/I.class

You then incorrectly invoke it as:

java -cp circular I

the error is:

Error: Could not find or load main class I
Caused by: java.lang.NoClassDefFoundError: circular/I (wrong name: I) 

but it should be:

Error: Could not find or load main class I
Caused by: java.lang.NoClassDefFoundError: I (wrong name: circular/I) 

because the VM was asked to load class I but couldn't find I; it found a classfile I.class, but that classfile identified the class in it as circular.I which is the wrong name.

There is obviously a matter of perspective on this but the error should reflect things from the user's perspective:

User: Hey JVM please load class I
JVM: Where should I look for it?
User: in the circular directory
JVM: NoClassDefFoundError: I
User: Hey it is in file I.class
JVM: No the class in that file has the wrong name: circular.I