hey I can no longer deleted nodes or doctypes in my installation, I am getting a POST delete 500 internal server error heres the stack trace:

{"Message":"Exception has been thrown by the target of an invocation.","StackTrace":"   at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner)\r\n   at System.RuntimeMethodHandle.InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeType typeOwner)\r\n   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)\r\n   at System.Delegate.DynamicInvokeImpl(Object[] args)\r\n   at umbraco.cms.businesslogic.CMSNode.FireCancelableEvent[T](EventHandler`1 cancelableEvent, Object sender, T eventArgs)\r\n   at umbraco.cms.businesslogic.CMSNode.FireBeforeMove(MoveEventArgs e)\r\n   at umbraco.cms.businesslogic.CMSNode.Move(CMSNode parent)\r\n   at umbraco.cms.businesslogic.web.Document.MoveToTrash()\r\n   at umbraco.cms.businesslogic.web.Document.delete()\r\n   at umbraco.contentTasks.Delete()\r\n   at umbraco.presentation.create.dialogHandler_temp.Delete(String NodeType, Int32 NodeId, String Text)\r\n   at umbraco.presentation.webservices.legacyAjaxCalls.Delete(String nodeId, String alias, String nodeType)","ExceptionType":"System.Reflection.TargetInvocationException"}

Does anyone have any ideas? this is quite crucial I get this solved? Thanks