I've tried to complete the trailhead challenge Connect to Salesforce with Server-Side Controllers and I'm getting the following error:
The Apex controller CampingListController doesn't have a 'getItems()' or 'saveItem(Camping_Item__c item)' method.

I've completed the following challenge (Connect components with events) and everything worked fine! Has anyone run across this problem before?

Following my code:

campingListController.js

({
    // Load camping items from Salesforce
    doInit: function(component, event, helper) {
        
        // Create the action
        var action = component.get("c.getItems");
        
        // Add callback behavior for when response is received
        action.setCallback(this, function(response) {
            var state = response.getState();
            if (component.isValid() && state === "SUCCESS") {
                component.set("v.items", response.getReturnValue());
            }
            else {
                console.log("Failed with state: " + state);
            }
        });
        
        // Send action off to be executed
        $A.enqueueAction(action);
    },
    
    handleAddItem: function(component, event, helper) {
        var action = component.get("c.saveItem");
        var item = event.getParam("item");
        action.setParams({
        "item": item
        });
        
        //console.log(event.getParam("item"));
        
        action.setCallback(this, function(response){
        var state = response.getState();
        if (component.isValid() && state === "SUCCESS") {
            var items = component.get("v.items");
            items.push(response.getReturnValue());
            component.set("v.items", items);
        }
        });
        $A.enqueueAction(action);
    }
})

CampingListController.apxc

public with sharing class CampingListController {

    @AuraEnabled
    public static List<Camping_Item__c> getItems() {
    
        // Check to make sure all fields are accessible to this user
        String[] fieldsToCheck = new String[] {
            'Id', 'Name', 'Packed__c', 'Price__c', 'Quantity__c'
        };
        
        Map<String,Schema.SObjectField> fieldDescribeTokens = 
            Schema.SObjectType.Camping_Item__c.fields.getMap();
        
        for(String field : fieldsToCheck) {
            if( ! fieldDescribeTokens.get(field).getDescribe().isAccessible()) {
                throw new System.NoAccessException();
                return null;
            }
        }        
        
        // Perform isAccessible() checking first, then
        return [SELECT Id, Name, Packed__c, Price__c, Quantity__c 
                FROM Camping_Item__c];
    }
    
    @AuraEnabled
    public static Camping_Item__c saveItem(Camping_Item__c item) {
        // Perform isUpdatable() checking first, then
        upsert item;
        return item;
    }
}

Any help welcome!
Thanks!

I've tried to complete the trailhead challenge Connect to Salesforce with Server-Side Controllers and I'm getting the following error:
The Apex controller CampingListController doesn't have a 'getItems()' or 'saveItem(Camping_Item__c item)' method.

I've completed the following challenge (Connect components with events) and everything worked fine! Has anyone run across this problem before?

Following my code:

campingListController.js

({
    // Load camping items from Salesforce
    doInit: function(component, event, helper) {
        
        // Create the action
        var action = component.get("c.getItems");
        
        // Add callback behavior for when response is received
        action.setCallback(this, function(response) {
            var state = response.getState();
            if (component.isValid() && state === "SUCCESS") {
                component.set("v.items", response.getReturnValue());
            }
            else {
                console.log("Failed with state: " + state);
            }
        });
        
        // Send action off to be executed
        $A.enqueueAction(action);
    },
    
    handleAddItem: function(component, event, helper) {
        var action = component.get("c.saveItem");
        var item = event.getParam("item");
        action.setParams({
        "item": item
        });
        
        //console.log(event.getParam("item"));
        
        action.setCallback(this, function(response){
        var state = response.getState();
        if (component.isValid() && state === "SUCCESS") {
            var items = component.get("v.items");
            items.push(response.getReturnValue());
            component.set("v.items", items);
        }
        });
        $A.enqueueAction(action);
    }
})

CampingListController.apxc

public with sharing class CampingListController {

    @AuraEnabled
    public static List<Camping_Item__c> getItems() {
    
        // Check to make sure all fields are accessible to this user
        String[] fieldsToCheck = new String[] {
            'Id', 'Name', 'Packed__c', 'Price__c', 'Quantity__c'
        };
        
        Map<String,Schema.SObjectField> fieldDescribeTokens = 
            Schema.SObjectType.Camping_Item__c.fields.getMap();
        
        for(String field : fieldsToCheck) {
            if( ! fieldDescribeTokens.get(field).getDescribe().isAccessible()) {
                throw new System.NoAccessException();
                return null;
            }
        }        
        
        // Perform isAccessible() checking first, then
        return [SELECT Id, Name, Packed__c, Price__c, Quantity__c 
                FROM Camping_Item__c];
    }
    
    @AuraEnabled
    public static Camping_Item__c saveItem(Camping_Item__c item) {
        // Perform isUpdatable() checking first, then
        upsert item;
        return item;
    }
}

Any help welcome!
Thanks!