When invokedynamic instruction or MethodHandles.convertArguments() needs to convert between primary types, an exception like the one below is thrown:

Exception in thread "main" java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.lang.Byte
        at sun.dyn.util.ValueConversions.unboxByte(ValueConversions.java:61)
        at sun.dyn.util.ValueConversions.unboxByteRaw(ValueConversions.java:98)
        at sun.dyn.ToGeneric$Adapter.return_I(ToGeneric.java:393)
        at sun.dyn.ToGeneric$A1.invoke_I(ToGeneric.java:643)

A short test case for this:

import java.dyn.*;

public class R {
    public static void main(String... args) throws Throwable {
        MethodHandle mh1 = MethodHandles.identity(int.class);
        MethodHandle mh2 = MethodHandles.convertArguments(mh1, MethodType.methodType(short.class, int.class));
        short s = (short) mh2.invokeExact(123);
    }
}