How did you generate or load the data in the first place? Are
you using DataService or RemoteObject? Any idea how big this object
is in terms of bytes or numbers of members of an Array, etc? Are
you using ArrayCollection or just plain old Array? Does it make a
difference if you switch between the two? If it's RemoteObject,
have you considered setting makeObjectsBindable to false to see if
it makes a difference?
There are theoretical limitations to certain data types but
they would be hard to reach, it would most likely be a circular
dependency somewhere that is breaking serialization. While circular
references are supported, custom serialization using
IExternalizable may circumvent reference checking based on the
custom encoding format.
Note out of interest that based on AMF encoding you are
limited to around 256MB for an individual String or ByteArray,
around 256 million unique object or string instances (as reoccuring
instances are sent by reference), around 256 million array entries,
around 33 million property names on an object, etc.