So following checking your class path is appropriate (I truly dump the complete classpath on startup) I then do a binary chop on class A. This may be an IDE bug. By way of example @Joel Costigliola explained a circumstance wherever Eclipse did not manage a Maven "check" tree properly: https://bongacam51616.thelateblog.com/36895139/considerations-to-know-about-bongacams-mature