Forgot to include the call stack:

   at System.Collections.ArrayList.get_Item(Int32 index)
   at Infragistics.Win.UltraWinTree.UltraTreeNode.IsFirstVisibleNodeInIslandHelper(Int32 topNodeVisibleIndex)
   at Infragistics.Win.UltraWinTree.UltraTreeNode.DisplaysHeaderAreaHelper(Int32 topNodeVisibleIndex)
   at Infragistics.Win.UltraWinTree.UltraTreeNode.get_DisplaysHeaderArea()
   at Infragistics.Win.UltraWinTree.NodeClientAreaUIElement.PositionChildElements()
   at Infragistics.Win.UIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive)
   at Infragistics.Win.UIElement.VerifyChildElements(Boolean recursive)
   at Infragistics.Win.UIElement.VerifyChildElements()
   at Infragistics.Win.UltraWinTree.UltraTreeUIElement.PositionChildElements()
   at Infragistics.Win.UIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive)
   at Infragistics.Win.UIElement.VerifyChildElements(Boolean recursive)
   at Infragistics.Win.UIElement.VerifyChildElements()
   at Infragistics.Win.UltraWinTree.UltraTreeNode.BringIntoViewHelper(Boolean includeChildNodes, Boolean includeHorizontal, Boolean includeVertical, Boolean leftOnly)
   at Infragistics.Win.UltraWinTree.UltraTreeNode.BringIntoViewHelper(Boolean includeChildNodes, Boolean includeHorizontal)
   at Infragistics.Win.UltraWinTree.UltraTree.SetActiveNode(UltraTreeNode node, Boolean bringIntoView, Boolean adjustHorizontalPosition)
   at Infragistics.Win.UltraWinTree.UltraTree.SetActiveNode(UltraTreeNode node, Boolean bringIntoView)
   at Infragistics.Win.UltraWinTree.UltraTree.SetActiveNode(UltraTreeNode node)
   at Infragistics.Win.UltraWinTree.UltraTree.set_ActiveNode(UltraTreeNode value)
     

Ok spent alot of time creating a proglet that pretends to do what
our real world application does and there is NO crash :¬(

But.... I did some random code slashing to see if i could get the problem to dissapear
and I found that twhen i moved the
ultraTree1->EndUpdate() before the ultraTree1->Active=keyNiode
the crash went away

I belive the crash is to do with our usage of
Node->Override->NodeAppearance and this setactive before the endupdate
but its a guess

--------------------FROM-------------------

// Begin Update
ultraTree1->BeginUpdate();
ultraTree1->Nodes->Clear();
ultraTree1->ImageList=imageList1;
for(i=0;i<40;i++){
  ultraTree1->Appearances->Add();
  ultraTree1->Appearances[i]->Image=i;
}

// DO LOTS OF NODE ADDS HERE

//
ultraTree1->ActiveNode=keyNode;
ultraTree1->ActiveNode->BringIntoView();

// End Update
ultraTree1->EndUpdate();

------------------- TO --------------------------

// Begin Update
ultraTree1->BeginUpdate();
ultraTree1->Nodes->Clear();
ultraTree1->ImageList=imageList1;
for(i=0;i<40;i++){
  ultraTree1->Appearances->Add();
  ultraTree1->Appearances[i]->Image=i;
}

// DO LOTS OF NODE ADDS HERE

// End Update
ultraTree1->EndUpdate();

//
ultraTree1->ActiveNode=keyNode;
ultraTree1->ActiveNode->BringIntoView();

-----------------------------------------------------

Yes, the cause is setting the ActiveNode while painting is suspended. That is of course a bug which will be addressed in a future release. The easiest solution for you is to move the ActiveNode assignment outside the BeginUpdate/EndUpdate block, since you gain nothing by having it in there anyway.

bmcloughlin and dpalau:

I've passed the information on this thread to Developer Support, so that a support case will be logged for each of you.  That way, you'll be notified when a service release containing the changes that Brian mentions is published.  The workaround Brian mentioned should get you up-and-running again in the meantime.

This issue seems resolved (for us, anyway) as of build 2029.  Thanks.

we are getting the same error too, how can i download build 2029.  Thanks.