The Deployment Server engine (axengine) is so busy processing logged-on user data from its clients that it experiences severe performance degradation which includes, but is not limited to, jobs failing to run.
The AClient/DAgent gathers each logged-on user's information and passes that information back to the Deployment Server engine (axengine). The engine then has to process each of these bits of information. Because of their roles, both Citrix and Microsoft Terminal Servers generate high volumes of logged-on user data that trigger the failure described by this article.
This issue has been resolved by adding a registry key to the Deployment Server and client(s) that opts to ignore changes to the list of logged on users. This registry key will work on AClient 6.9.453 (SP4) or DAgent version 6.9.490 (SP5) and newer.
You will first need to adjust the registry settings on the Deployment Server. Otherwise the changes made to the registry on the client will revert back to their previous setting. This is done here: