ISO: techniques for resolving "not a valid WDDX packet" errors

Question

I
inherited (more honestly - I was drafted into maintaining) a
large and probably not very well written web app written in
ColdFusion. My coldfusion experience is minimal - I took a course
back in the 4.0 days, and really didn't have much need to deal with
it until now.
Anyways, the inherited application, when attempting to
display one particular record, outputs the message that the field
being displayed "is not a valid WDDX packet". I've gone to the
database entry for this record, dumped the contents (which is a
couple thousand bytes of XML).
How can I figure out what in the data is wrong, so that I can
hack a solution into place?

Answer 1

The site in question is a workflow/purchase request
application. The applicant fills in the details, and the coldfusion
bundles up the structure as wddx and wites it out to a database.
Then, later, when the next person in the work flow needs to read
the details, the database record is retrieved, the xml interpreted
and the structure filled in, and then they can add details, provide
approval or disapproval, update the record, and the request moves
on to the next step in the work flow.
Just as you suggested, my first thought was to get at the
data in question to see if I could determine what the problem is. I
have tried the url 'directly' - it is the only URL I have for the
operation. All I get, as I mentioned before, is a coldfusion
message about the data not being a valid wddx packet.
What I need is some method of determining to what coldfusion
is specifically objecting.