Hello,
chartHelper run as system but still getting error. I have tried all possible ways but no luck. Can someone please help. 

Challenge Not yet complete... here's what's wrong: 
Ensure that the methods in the chartHelper class run as the system.

ChartHelper.apxc

public class ChartHelper {
    
    @AuraEnabled// Make sure annotation should be pplied for this method 
    public static List<chartData> GetInventory()
    {
        
        List<chartData> cht = new List<chartData>();
        
        for(AggregateResult ar : [SELECT Family family, Sum(Quantity_Remaining__c) total 
                                  FROM Product2
                                  WHERE Quantity_Remaining__c > 0 GROUP BY Family]){
                                      cht.add(new chartData((String)ar.get('family'), Integer.valueOf(ar.get('total'))));
                                  }
        return cht;
    }
    
    public class ChartData {
        public String name {get;set;}
        public Decimal val {get;set;}
        
        public ChartData(String name, Decimal val){
            this.name = name;
            this.val = val;
        }
    }
    
}

Product2Extension​.apxc

public class Product2Extension {

    public List<ProductWrapper> productsToInsert {get;set;}

    public Product2Extension(ApexPages.StandardController controller){
        productsToInsert = new List<ProductWrapper>();
        addRows();
    }
	
    public List<SelectOption> GetFamilyOptions() {
		List<SelectOption> options = new List<SelectOption>();
        options.add(new SelectOption(Constants.SELECT_ONE, Constants.SELECT_ONE));
        for(PickListEntry eachPicklistValue : Constants.PRODUCT_FAMILY) {
			options.add(new SelectOption(eachPicklistValue.getValue(), eachPicklistValue.getLabel()));
        }
            return options;
    }
    
    public void AddRows(){
        for (Integer i=0; i<Constants.DEFAULT_ROWS; i++ ){
            productsToInsert.add(new ProductWrapper());
        }
    }

    public List<ChartHelper.ChartData> GetInventory(){
        return ChartHelper.GetInventory();
    }

    public PageReference Save(){
        SavePoint sp = Database.setSavepoint();
        Integer insertedCount = 0;
        try {
            List<Product2> newProducts = new List<Product2>();
            List<PriceBookEntry> pbeList = new List<PriceBookEntry>();
            List<ProductWrapper> filteredProductWrappers = new List<ProductWrapper>();
            for(ProductWrapper eachPW : productsToInsert) {
            	if(!String.isBlank(eachPW.productRecord.Name) && !String.isBlank(eachPW.productRecord.Family) && 
                   eachPW.productRecord.Family!=Constants.SELECT_ONE && eachPW.productRecord.isActive &&
                   eachPW.pricebookEntryRecord.UnitPrice!=null && eachPW.productRecord.Initial_Inventory__c!=null && 
                   eachPW.productRecord.Initial_Inventory__c!=0 && eachPW.pricebookEntryRecord.UnitPrice!=0) {
                       filteredProductWrappers.add(eachPW);
                   }                
            }
            for(ProductWrapper eachPW : filteredProductWrappers) {
                newProducts.add(eachPW.productRecord);
            }
            Database.SaveResult[] productSaveResults = Database.insert(newProducts, false);
            for(Integer i=0; i<productSaveResults.size(); i++) {
                if(productSaveResults[i].isSuccess()) {
                    PriceBookEntry pbe = filteredProductWrappers[i].pricebookEntryRecord;
                    pbe.Product2Id = productSaveResults[i].getId();
                    pbe.IsActive = true;
                    pbe.Pricebook2Id = Constants.STANDARD_PRICEBOOK_ID;
                    pbeList.add(pbe);
                    insertedCount++;
                }
            }
            Database.SaveResult[] pbeSaveResults = Database.insert(pbeList, false);
            
            //If successful clear the list and display an informational message
            apexPages.addMessage(new ApexPages.message(ApexPages.Severity.INFO,insertedCount + ' Inserted'));
            productsToInsert.clear();   //Do not remove
            addRows();  //Do not remove
        } 
        catch (Exception e){
			System.debug('Exception occured:'+e.getMessage());
            Database.rollback(sp);
            apexPages.addMessage(new ApexPages.message(ApexPages.Severity.ERROR, Constants.ERROR_MESSAGE));            
        }
        return null;
    }
    
    public class ProductWrapper {
        public Product2 productRecord {get;set;}
        public PriceBookEntry pricebookEntryRecord {get;set;}
        
        public ProductWrapper() {
            productRecord = new Product2();
            pricebookEntryRecord = new PricebookEntry();
        }
	}
}

Product2New.vfp

<apex:page standardcontroller="Product2" extensions="Product2Extension">
    <apex:sectionHeader title="New Product" subtitle="Add Inventory" />
    <apex:pageMessages id="pageMessages" />
    <apex:form id="form" >
        <apex:actionRegion >
            <apex:pageBlock title="Existing Inventory" id="existingInv">
                <apex:chart data="{!Inventory}" width="600" height="400">
                    <apex:axis type="Category" fields="name" position="left" title="Product Family"/>
                    <apex:axis type="Numeric" fields="val" position="bottom" title="Quantity Remaining"/>
                    <apex:barSeries axis="bottom" orientation="horizontal" xField="val" yField="name"/>
                 </apex:chart>                
            </apex:pageBlock>
            <apex:pageBlock title="New Products" >
                <apex:pageBlockButtons location="top">
                    <apex:commandButton action="{!save}" value="Save" reRender="existingInv, orderItemTable, pageMessages"/>
                </apex:pageBlockButtons>
                <apex:pageBlockButtons location="bottom">
                    <apex:commandButton action="{!addRows}" value="Add" reRender="orderItemTable, pageMessages" />
                </apex:pageBlockButtons>

                <apex:pageBlockTable value="{!productsToInsert}" var="p" id="orderItemTable" >
                    <apex:column headerValue="{!$ObjectType.Product2.Fields.Name.Label}" >
                        <apex:inputText value="{!p.productRecord.Name}" />
                    </apex:column>
                    <apex:column headerValue="{!$ObjectType.Product2.Fields.Family.Label}" >
                        <apex:selectList value="{!p.productRecord.Family}" size="1" multiselect="false">
                            <apex:selectOptions value="{!FamilyOptions}"></apex:selectOptions>
                        </apex:selectList>
                    </apex:column>
                    <apex:column headerValue="{!$ObjectType.Product2.Fields.IsActive.Label}" >
                        <apex:inputField value="{!p.productRecord.isActive}" />
                    </apex:column>
                    <apex:column headerValue="{!$ObjectType.PricebookEntry.Fields.UnitPrice.Label}" >
                        <apex:inputText value="{!p.pricebookEntryRecord.UnitPrice}" />
                    </apex:column>
                    <apex:column headerValue="{!$ObjectType.Product2.Fields.Initial_Inventory__c.Label}" >
                        <apex:inputField value="{!p.productRecord.Initial_Inventory__c}" />
                    </apex:column>
                </apex:pageBlockTable>
            </apex:pageBlock>
        </apex:actionRegion>
    </apex:form>
</apex:page>