Just looking at this under jdk9 build 126 and the full error is:
java.lang.IllegalAccessException: class org.jboss.weld.util.reflection.Formats cannot access class com.sun.org.apache.bcel.internal.classfile.ClassParser (in module java.xml) because module java.xml does not export com.sun.org.apache.bcel.internal.classfile to unnamed module @69b794e2

This is happening on line 172 where Formats is trying to create an instance of ClassParser:
Object parser = classParserClass.getConstructor(InputStream.class, String.class).newInstance(in, classFile);