I have some code which has been working for almost a year which has suddenly stoped working. It involves creating a Map<String, Wrapper> called selectedItems in the apex controller, using apex:repeat to iterate over the object in visualforce. There is a check box which when check or unchecked fires actionFunction to to the apex controller to either remove or add the item to the selectedItems Map and then rerenders the apex:outputPanel where the selectedItems is displayed.  The following is something i threw together to duplicate the problem as the actual code is much more involved and this is the problem I am facing.

Apex Controller

public with sharing class TestMapError {

  public Map<Id, Product2> prodMap { get; set; }
  public Map<Id, Product2> selectedMap { get; set; }

	public TestMapError() {
    prodMap = new Map<Id, Product2>([SELECT Id, Name FROM Product2 WHERE isActive = true LIMIT 5]);
    selectedMap = new Map<Id, Product2>();
	}

  public void toggleSelect()
  {
    String pId = Apexpages.currentPage().getParameters().get('pId');
    if( selectedMap.containsKey(pId) )
    {
      selectedMap.remove(pId);
    }
    else
    {
      selectedMap.put(pId, prodMap.get(pId) );
    }
  }

}

Visualforce Page
 

<apex:page showHeader="true" sidebar="true" controller="TestMapError">
  <apex:includeScript value="{!URLFOR($Resource.jQuery)}"/>

  <apex:form>

    <apex:actionFunction name="toggleSelected"
                         action="{!toggleSelect}"
                         rerender="selectedList">
      <apex:param name="pId" value="" />
    </apex:actionFunction>

    <apex:outputPanel id="theList">
      <ul>
        <apex:repeat value="{!prodMap}" var="prodId">
          <li>
            {!prodMap[prodId].Name}
            <input type="checkbox" data-pid="{!prodId}" onChange="toggleCheck(this);"/>
          </li>
        </apex:repeat>
      </ul>
    </apex:outputPanel>

  </apex:form>
  <br />

  <apex:outputPanel id="selectedList">
    <h3>Selected</h3>
     <ul>
      <apex:repeat value="{!selectedMap}" var="sId">
        <li>{!selectedMap[sId].Name}</li>
      </apex:repeat>
    </ul>
  </apex:outputPanel>

  <script type="text/javascript">

  var $j = jQuery.noConflict();


    function toggleCheck(ele)
    {
      console.log( $j(ele).data('pid'));
      toggleSelected( $j(ele).data('pid') );
    }

  </script>

</apex:page>

When the check box is selected, the first Item is not rendered in the selected list, but if you select a second item the first shows up.  If you check the view state, both items are present in the selectedMap.  Then if you uncheck any of the checked boxes you get a visualforce error of Map key not found in Map.

This used to work up until very recently and I did recieve an email from Salesforce stating they are upgrading to JDK 8.  Is it possible this is the underlying problem? Any help on this would be greatly appreciated