Tag: Error

I am trying to add permission to the list which I have created in my app. I am trying to give current user some permission to add update delete items from my list. I have used one article from MSDN site. And my code is as bellow:

function execOperation() {     debugger;     context = new SP.ClientContext(appweburl);     var factory =         new SP.ProxyWebRequestExecutorFactory(             appweburl         );     context.set_webRequestExecutorFactory(factory);     appContextSite = new SP.AppContextSite(context, appweburl);     var appContextSite2 = new SP.AppContextSite(context, hostweburl);      var siteColl = appContextSite2.get_site();     hostweb = appContextSite2.get_web();     context.load(hostweb);      web = appContextSite.get_web();     context.load(web);     user = web.get_currentUser();     context.load(user);     que_list = web.get_lists().getByTitle("MyList1");     context.load(que_list);     que_list.breakRoleInheritance(true, true);      var permissions = new SP.BasePermissions();     permissions.set(SP.PermissionKind.viewListItems);     permissions.set(SP.PermissionKind.addListItems);     permissions.set(SP.PermissionKind.editListItems);     permissions.set(SP.PermissionKind.deleteListItems);      // Create a new role definition.     var roleDefinitionCreationInfo = new SP.RoleDefinitionCreationInformation();     roleDefinitionCreationInfo.set_name('Manage List Items');     roleDefinitionCreationInfo.set_description('Allows a user to manage list items');     roleDefinitionCreationInfo.set_basePermissions(permissions);     var roleDefinition = web.get_roleDefinitions().add(roleDefinitionCreationInfo);      web.breakRoleInheritance(true, false);     // Create a new RoleDefinitionBindingCollection.     var newBindings = SP.RoleDefinitionBindingCollection.newObject(context);     // Add the role to the collection.     newBindings.add(roleDefinition);      // Get the RoleAssignmentCollection for the target list.     var assignments = que_list.get_roleAssignments();     que_list.breakRoleInheritance(true, true);     // Add the user to the target list and assign the use to the new RoleDefinitionBindingCollection.     var roleAssignment = assignments.add(web.get_currentUser(), newBindings);      context.executeQueryAsync(onSuccess, onFail); } 

I have just copied the code from that article. But when I run my app it give me error :

You cannot customize permission levels in a web site with inherited permission levels 

Any suggestions, What am I doing wrong?
Any help will be appreciated…! Thank you in advance…!