Error – The user does not exist or is not unique SharePoint 2010

Currently I was doing some settings for super account
In this context, I executed below command in powershell window.

stsadm -o setproperty -propertyname portalsuperreaderaccount -propertyvalue account -url “<site-url>”

But my site stops working and got below screen while access url with error message.

“The user does not exist or is not unique SharePoint 2010“

So I search this query in google “super reader account sharepoint 2010 remove” and found the solution.

I executed below command in powershell window.

$wa = Get-SPWebApplication -Identity “<site-url>”
$wa.Properties.Remove(“portalsuperuseraccount”)
$wa.Properties.Remove(“portalsuperreaderaccount”)
$wa.Update()

It works for me.