The error below could result when performing an administrative task with the Skype for Business Control Panel or running a cmdlet in the management shell.
PS C:\Users\administrator> Get-CsUser user01
Get-CsUser : A connection was successfully established with the server, but
then an error occurred during the pre-login handshake. (provider: SSL Provider, error: 0 – The wait operation timed out.)
At line:1 char:1
+ Get-CsUser user01
+ CategoryInfo : NotSpecified: (:) [Get-CsUser], SqlConnectionExc
+ FullyQualifiedErrorId : Microsoft.Rtc.Common.Data.SqlConnectionException
To resolve, ensure that the host machine has sufficient RAM memory and/or close unneeded running applications. This fix applies even if the Windows operating system appears to be running with adequate memory. Otherwise, a machine reboot may be in order.