Hello, in a product I try to make a file object persistent with the _setObject() method. However I get the error: Error Value: 'File' object has no attribute 'manage_fixupOwnershipAfterAdd' The following is the code where the error occurs: cpu_load = self.getCpuLoad(id,location_sar,f_time,l_time) system.cpu_load_file=File(data=cpu_load[0], contentType='text/plain') self.tgt_folder[id]._setObject('cpu_load',system.cpu_load_file) This is done in the __init__ method of the class. The class subclasses from Folder and SimpleItem. self.tgt_folder[id] has been created a few lines above by: self.tgt_folder[id]=Folder() self._setObject(id,self.tgt_folder[id]) The container that holds self.tgt_folder[id] is a BTreesFolder2. I know that the file Object is pretty simple, but how can one create and persist it if not with the _setObject() method? Thanks in advance Roman