Edit network dataset source from web client

Discussion created by yo_haha on Mar 7, 2013

I'm working with a NA dataset containing edge and vertex sources.
I want to be able to modify the features of those sources from a web flex client. So I created a python geoprocessing that updates the targeted features using update cursors and published it as a gp service.
When I execute the gp from ArcMap or ArcCatalog, everything gets updated as it should and I get no errors.
But when I call the gp from the web client, sometimes I get the error below (from AGS server):

ERROR 999999: Error executing function. Objects in this class cannot be updated outside an edit session [featureClass] Failed to execute (py_gp). Failed at Thu Mar 07 16:13:37 2013 (Elapsed Time: 3,00 seconds)

Sometimes I get no error but the data just dont get updated.

Do you have any idea why this is happening?