title: Lightning Component not showing on Lightning Tab
body: <p>I am not able to see my lightning component when trying to create a lighting tab. Something is wrong with one of the components - </p>
  
  <p>I moved the component and tab using salesforce dx and when editing the component. I am getting below error. I seems like one of the component is throwing an error when i am trying to edit the record - </p>
  
  <p>Error = Review all error messages below to correct your data.
  You can only create lightning tabs for AuraDefinitionBundles containing a component that implements force:appHostable and has no required attributes without a default value. (Related field: Content)</p>
  
  <p>Observation - When i remove the attribute from parent component and child component than its working and i am able to save the tab. Something is not correct with my component initiation.</p>
  
  <p>Code in parent Component - </p>
  
  <pre><code>&lt;aura:if isTrue="{!!v.customTab}"&gt;
  &lt;div aura:id="defaultTabContent" class="slds-show"&gt;
      &lt;c:ApiRequestFieldMapping custom="false" objectName="Credit_Report__c"/&gt;
  &lt;/div&gt;
  &lt;/aura:if&gt;
  &lt;aura:if isTrue="{!v.customTab}"&gt;
  &lt;div aura:id="customTabContent" class="slds-hide"&gt;
      &lt;c:ApiRequestFieldMapping custom="true" listSObjects="
      {!v.listSObjects}" message="Select object from drop-down." 
      messageClass="Info"/&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Code in Child Component - </p>
  
  <pre><code>&lt;aura:handler name="init" action="{!c.doInit}" value="{!this}"/&gt;
  &lt;aura:registerEvent name="handleModelVisiblity" type="c:HandleModel"/&gt;
  &lt;!-- attributes --&gt;
  &lt;aura:attribute name="custom" type="Boolean"/&gt;
  &lt;aura:attribute name="objectName" type="String"/&gt;
  &lt;aura:attribute name="listSObjects" type="String[]"/&gt;
  &lt;aura:attribute name="message" type="String"/&gt;
  &lt;aura:attribute name="messageClass" type="String"/&gt; 
  &lt;aura:attribute name="listSObjectFields" type="String[]" 
  required="false"/&gt;
  &lt;aura:attribute name="customObjectName" type="String" 
  required="false"/&gt;
  &lt;aura:attribute name="listWrapper" 
  type="RequestMappingWrapper.MappingRecords[]" required="false"/&gt;
  </code></pre>
  
  <p>Already Tried - 1. My component is already implementing "force:appHostable" interface.
  2. The component us using latest version.(40.0)
  3. Have already tried creating the components.
  4. My org has my domain enabled and also have namespace.</p>