If you are trying to get Flex to run on Google App Engine, the current blazeds implementation does not support appengine:
See Adobe’s BLZ-444 Feature Request for more info.
However, there are workarounds. If you google blazeds and appengine, you will find some.
One such workaround can be found on Martin Zoldano’s blog post on the subject. We’ve tried this fix and it works.
Let us know if there are any other workarounds that folks prefer out there…
Kind regards,
Dave