How do I resolve this error when I run my program? I can pinpoint that it has to do with adding a string to the ArrayList in the doubleValues(ArrayList<String list>) method. When I use the loop to print out the list it runs just fine. java.util.ConcurrentModificationException at java.util.ArrayList$Itr.checkForComodification( at java.util.ArrayList$ at com.codegym.task.task07.task0717.Solution.doubleValues( at com.codegym.task.task07.task0717.Solution.main( at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke( at sun.reflect.DelegatingMethodAccessorImpl.invoke( at java.lang.reflect.Method.invoke(