Getting insufficient privileges error message, when popup opens

Question

I have a popup on buttonclick visualforcepage. When the popup opens, I'm getting the below error message:

Insufficient Privileges You do not have the level of access necessary to perform the operation you requested.

Vforce Code:

<script>

  function RLPopup(aid){
    alert('here' + aid);
    var newwindow = window.open('RELNameChangePopup', 'name=_blank','height=500,width=500,left=250,top=100');
    newwindow.focus();
    }
</script>

Button:

      <apex:commandbutton value="Edit" id="accpopup" 
       onclick="LegalNameChangePopup('{!aaccount.id}');" styleclass="btn"/>

Popup Page: RELNameChangePopup

    <apex:page standardcontroller="RL_Info__c" 
    extensions="RLInfoController" showheader="false" sidebar="false">
    <apex:form id="page"> 
      <apex:pageBlock >
      <apex:pageBlockSection columns="1" title="Name change"> 
     <apex:pageblocktable value="{!aAccount}" var="item" 
    id="editAccountName">
      <apex:outputfield id="accountName" value="{!item.name}"/>
    <apex:outputfield id="accountId" value="{!item.id}"/>
      <apex:column headervalue="Proposed Name">
      <apex:inputtext value="{!item.Name}" />
      </apex:column> </apex:pageblocktable>
       </apex:pageBlockSection> 
    </apex:pageBlock>
   </apex:form>
   </apex:page>

From the controller I'm getting the accountID and account Name.

TIA

Answer 1

I found the issue. The profile was missing the new controller I have added.