When a class extends a raw superclass, and overrides a method from it, the compiler issues a confusing error message. Example:

class A<T> {
    void foo(Clazz<?> clazz) { ... }
}

class B extends A /* raw A here */ {
    @Override
    void foo(Clazz<?> clazz) { ... }
}

The error message is:
error: name clash: run(Class<?>) in A and run(Class<?>) in B have the same erasure, yet neither overrides the other

What is happening is that when you extend a raw type, the method descriptors are erased; at least the message should say run(Class<?>) and run(Class) to make it clear that erasure is the problem.