I keep getting `$A.getCallback() [Cannot read property of null` when I start typing in the text fields of a form. I referred this link - https://salesforce.stackexchange.com/questions/166636/lightning-error-in-a-getcallback to see if this solves the problem, I do not have an apex class yet and I try to add the default values for the `boatReview attribute`. `default="{'sobjectType:'BoatReview__c','Name':'','Comment__c':''}"` Which gave the error on page load:

[![enter image description here][1]][1]

Before adding the default I have the component as below:

    <aura:component description="AddBoatReview">
    <aura:attribute name="boat" type="boat__c"/>
    <aura:attribute name="boatReview" type="BoatReview__c" access="private"/>
        <aura:attribute name="recordRecord" type="String" access="private"/>
        <aura:attribute name="recordSaveError" type="String" access="private"/>
        <aura:handler name="init" value="{!this}" action="{!c.doInit}" />
        <!-- <force:recordData aura:id="service"
                          layoutType="FULL"
                          recordId="{!v.boatReview.Id}"
                          fields="Id, Name, Comment__c, Boat__c"
                          targetError="{!v.recordSaveError}"
                          targetRecord="{!v.recordRecord}"
                          targetFields="{!v.boatReview}"
                          mode="EDIT"
                          recordUpdated="{!c.onRecordUpdated}"/> -->
    
        <form class="slds-form--stacked">
            <lightning:input aura:id="boatRevw" label="Title"
                             value="{!v.boatReview.Name}"/>
            <lightning:inputRichText aura:id="boatRevw" title="Description"
                             value="{!v.boatReview.Comment__c}"/>
            <lightning:button label="Submit"
                              class="slds-m-top--medium"
                              iconName="utility:save"
                              variant="brand"
                              onclick="{!c.onSave}"/>
        </form>
    </aura:component>

Controller:

    ({
        doInit:function (component,event,helper) {
            var eventParams = event.getParams();
            helper.onInit(component,eventParams);
        },
        onRecordUpdated:function (component,event,helper) {
    
        },
        onSave:function (component,event,helper) {
            console.log('Enters the Save method');
            var recordData = component.find("service");
        }

    })

Helper does nothing, just have a `onInit` sitting there.

I get the below error when I type a letter in text fields:

[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/nc8nP.png
  [2]: https://i.sstatic.net/5in1w.png