Troubles installing TelnetClient

Question

From an administrator PowerShell prompt:

PS> Enable-WindowsOptionalFeature -Online -FeatureName TelnetClient

Enable-WindowsOptionalFeature : The referenced assembly could not be found.
At line:1 char:1
+ Enable-WindowsOptionalFeature -Online -FeatureName TelnetClient
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Enable-WindowsOptionalFeature], COMException
    + FullyQualifiedErrorId : Microsoft.Dism.Commands.EnableWindowsOptionalFeatureCommand

It also reports a similar error if I try to do it through "Programs and Features".