http://livedocs.adobe.com/ Macromedia LiveDocs - online documentation with user feedback. Copyright 2009, Macromedia, Inc. 2009-11-25T16:19:31 en-us http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/filesystem/FileStream.html#83745 @Zimmen:<br><br>That can be the case, depending on the class. Most classes can be serialized, but some can't. The most notable exception is display objects -- they can't be serialized using writeObject() (or more correctly, they can be serialized, but they come back as generic objects with as many properties as possible). The reason for this is because a lot of the state of a display object -- things like whether it contains children, whether it's on the stage or not, whether it has content drawn into it via the drawing api -- is a characteristic of the state of the object at a moment in time and depends on external factors that can't be guaranteed at deserialization time.<br><br>Having said that, as long as your custom class doesn't refer to an object that can't be deserialized, it should be able to be saved and recreated using writeObject() and readObject(). However, in order to do so you must first register an alias for the class using the flash.net.registerClassAlias() method. You must register the alias before serializing the object, and also you must register the same alias for the same class before deserializing the object. That alias is what the runtime uses to match the data to your custom class. adbe_paul 1 0 2008-05-06T13:45:53 http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/filesystem/FileStream.html#83723 Using writeObject to write a cusom class to disk does not work like expected. it cannot convert the object that gets read by readObject back to it's original type and it cannot access private properties using a getter when there is no setter available. It looks as if the writeObject tries to do a simple copy of the Class instance into an Object instance before writing it to disk. Zimmen 0 0 2008-05-06T05:20:38