This warning occurred in a Windows 2000 environment after our 90 day terminal service grace period expired. Since all our clients have Windows XP Pro this was not an issue. Starting the terminal service licensing service solved the problem. If clients are non-XP Pro you will need to purchase seat or device licenses.
This event can also occur when trying to add existing Windows XP clients into an SBS 2K3 domain. When adding clients using the URL http://<servername>/ConnectComputer you may see the error message: "The list of user and computers could not be found on the server. Make sure that the Small Business Server network adapters are configured correctly”.
To fix this problem, check the network properties on the client. Make sure that the only DNS server set either statically or by DHCP is that of the SBS. Then browse again to http://<servername>/ConnectComputer.
As per Microsoft: "This computer cannot accept Layer Two Tunneling Protocol (L2TP) virtual private network (VPN) calls because it does not have an L2TP computer certificate installed". See MSW2KDB
for more details.
After I received the above error, I could no longer access the Exchange server from my home computer. I some how ended up with missing registry keys. I typed them back in and I could connect back in.
Verify that the “HKEY LOCAL MACHINE\Software\Microsoft\Rpc\ClientProtocols” registry key is not absent. It may have been removed by mistake.
The values most commonly displayed are listed below, and may be tried as well:
ncacn http : REG SZ : rpcrt4.dll
ncacn ip tcp : REG SZ : rpcrt4.dll
ncacn nb tcp : REG SZ : rpcrt4.dll
ncacn ip udp : REG SZ : rpcrt4.dll
Another possible solution for this problem is to un-install, and then re-install the File and Print Service. Since the File and Print Service is responsible for installing the RPC Server Service, and Client for Microsoft Networks installs the RPC Locator Service, re-installing these may also add the necessary components.
In Windows 2000, you can use a certificate server to authenticate Layer 2 Tunneling Protocol (L2TP) virtual private network (VPN) connections. If you have a server that has Routing and Remote Access Services (RRAS) configured and has active L2TP ports, you may receive event id 20192 error messages in the System event log. If you don’t want to use L2TP then simply disable these messages by following the steps described in ME245476