When I debug my encrypted project, I get a java.lang.NoClassDefFoundError

Currently, there are three ways to implement a Java debugger or profiler:

• java.lang.instrument (-javaagent)
• jvmti (-agentlib/-agentpath)
• jvmpi (-Xrun)

It is possible to get Java bytecode by all of these ways. Therefor ClassGuard detects Java debuggers and refuses to decrypt any classes in case of any running debugger.