Working in Notification Server, you see a yellow box in the top right corner that says, "Attention Required." If you click on it, "Resume NS Activities" is greyed out. You may also see messages similar to "The current user is not the member of Symantec Administrators and cannot resume server activity."
The reason for the message "Attention Required" are numerous and may need to be addressed by looking at the logs/Log Viewer.
The reasons you see messages about the current user (and you are confident you are in the Symantec Administrators role) is that the user(s) have become damaged.
You can attempt repairs by doing the following:
Right click on the following files and run 'Repair'