AD SYSVOL Share availability monitor. The SYSVOL share is essential to the health of the domain controller, and it needs immediate administrator attention.
The domain controller cannot advertise until this problem is fixed. Clients are unable to locate this domain controller at this time.
http://go.microsoft.com/fwlink/?LinkId=25827
Ultrasound shows health ratings and historical information about FRS replica sets. You can use it to monitor the progress of replication and to detect problems that can cause replication to become backlogged or stop. Ultrasound also provides detailed views for troubleshooting and a framework that you can use to customize alerts and views for your organization.
Verify that the SYSVOL security settings are correctly configured and that SYSVOL has not been accidentally unshared.