exception class EListError with message 'Unbalanced stack or queue operation'.

exception class EListError with message 'Unbalanced stack or queue operation'.

This little beastie has started popping up when the IDE launches my Android app. The app fails to start manually. The 32bit version works.
I have traced the exception to
{$IF Defined(AUTOREFCOUNT)}
procedure TStackHelper.InternalDoPopObject(Notification: TCollectionNotification; Peek: Boolean; out Item);
begin
CheckEmpty;
TObject(Item) := PObject(FItems^)[FLH.FCount - 1];
if not Peek then
begin
PObject(FItems^)[FLH.FCount - 1] := nil;
PopAdjust(Item, Notification);
end;
end;
{$ENDIF}

procedure TStackHelper.CheckEmpty;
begin
if FLH.FCount = 0 then
raise EListError.CreateRes(@SUnbalancedOperation);
end;
I cannot step into this code, it only shows the message.
I have activated madexcept v4 but it has not helped.

Can someone show/help me how to track down the cause?
Delphi CE, win10.

Thanks...Dan'l