The stamp xxx of location BLU is marked as inactive and cannot be updated

Question

I'm trying to restart web application deployed to service plan of my app service environment

I've got an error

Restart-AzureRmWebApp -ResourceGroupName myrg -Name webappname

Restart-AzureRmWebApp : The stamp asename of location BLU is marked as inactive and cannot be updated.
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : CloseError: (:) [Restart-AzureRmWebApp], CloudException
    + FullyQualifiedErrorId : Microsoft.Azure.Commands.WebApps.Cmdlets.WebApps.RestartAzureWebAppCmdlet

What is this error mean?