The most common cause of this problem is that a program that links to
user32.dll was run in a context in which it could not talk to the system's window station and desktop. Normally, a service such as the agent runs in its own window station and desktop, and
user32 programs run fine, but any program that displayed a dialog box would then hang without any opportunity for a human being to see the error message or close the dialog.
The agent takes the following measures to avoid this problem:
All programs executed by the agent talk to the default window station and desktop
All the agents are run as users with Administrator privileges; the default ACL for the default window station and desktop give full control to the Administrator group.
ecagentsvc.exe, the service that starts the agents, edits the ACL of the default window station and desktop to grant full access to the agent users, whether or not they're in the Administrator group. However, this ACL change is fragile, because anyone logging in or out on the system console will destroy and re-create the default window station and desktop.
If this problem occurs, check to ensure that the ACL is not a problem:
Start the Task Manager and verify that all agents are running as ECloudInternalUser_N_.
Go to the system's Administrative Tools, open Computer Management, and verify that all ECloudInternalUser_N_ users are members of the local Administrators group.