There are Currently No Logon Servers Available

How are they connecting to the network?  VPN, remote office, etc.  I'd say something is interfering with their connection to the network, DNS, firewall, etc.

netlogon service on server not working, no connection to AD server

Here is a bit more detail...  The remote users came into the office today and connected to their docking stations, Voila! works fine.  They remove it from the dock (hibernate), goes home, wakes from hibernation and...  "There are currently no logon servers available to service the logon request".   Hmmmmmmm.

Ok, you need to look between the office and their houses.

Sounds like a VPN issue.  You can always run a NetMon trace from their laptop while they are connecting in and see if that turns anything up.

Do you have wireless in the office?  Does that work?

when they resume from hibernate the system expects things to be the same.. have them shutdown before changing locations.

That IS the bandage that we are currently using:  Shutdown before leaving the office, no Sleep mode, no Hibernation mode.

We are looking for the root cause of our issue.  It only stopped working yesterday.  We've been fine for years working from home via VPN client, no matter if the user selected Sleep mode, Hibernation mode or system shutdown.

Any help would be greatly appreciated...  you know how people hate change, and our Sr Staff are not a very understanding lot.

Then the next question is...What changed?  Firmware update, network configuration, etc.  Something doesn't work for years then not work unless something is different.

That was the first angle we pursued...  We cannot determine what has happened.  We didn't even push the last Win update.

updates are always PULL never push

Thanks Adam!!

Dave, how does your comment help us in any form?

We didn't even push the last Win update. it is just a point of clarification