Hi James,
I am hoping that you can help me. I am also trying to applyEdits with the use of the javascript REST API. I am getting an "Unable to apply edits" general error. I have seen documentation that says to apply write permissions to ARCGISSOC through the "database server" node of ArcCatalog. However, it seems as if the "database server" node works with a SQLExpress instance, not a networked SQLserver SDE geodatabase. I see that you mention "grant" permissions. I have gone into SQL, right-clicked (on the geodatabase, not on a specific featureclass table), properties, permissions tab, and checked the "grant" box for connect, delete, execute, insert, select and update. applyEdits is still not working for me. Can you tell me what I need to do to apply the proper permissions? Is there a place in ArcCatalog to set a write permission on SQL SDE...that you know of? Anything I need to do in ArcCatalog? Thanks for any direction you can give!