Error in Salesforce Ligthning component

Hi all,

trying to build a lightning component but flashing this error

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Assertion Failed!: Unknown controller action 'clickCreateCampingList' : undefined
Failing descriptor: {ui$button$controller$press}

CONTROLLER
({
clickCreateCampingList: function(component, event, helper) {

// Simplistic error checking
var validCampinglist = true;

// Name must not be blank
var nameField = component.find("expname");
var expname = nameField.get("v.value");
if ($A.util.isEmpty(expname)){
validExpense = false;
nameField.set("v.errors", [{message:" name can't be blank."}]);
}
else {
nameField.set("v.errors", null);
}

// ... hint: more error checking here ...

// If we pass error checking, do some real work
if(validCampinglist){
// Create the new camping list
var newitem = component.get("v.newitem");
console.log("Create campingList: " + JSON.stringify(newitem));
helper.createCampinglist(component, newitem);
}
}
})