Users can't download XAR files on CNDA after system migrated to multinode configuration.
Root cause is that DIRResource restlet tries to write experiments in the XAR into XML files in the user cache space. It never checks to see if the folder for the current user exists in the cache folder. On the old server, this usually worked because people had done something in the past to cause the cache folder to be created, but on the new configuration you can't count on that folder being there.
Add a UserDataCache service that abstracts away where and how the user cache is stored and how anything happens under there, then integrate in place of piecemeal calls to various configuration services and creating files on the fly.