This error occurred when catalog name is null or empty
To fix This follow these steps
1. Find sessionstate tag in the web.config
By default it is 20 min increase to 60 min (Depends on requirement )
2. If your maintaining catalog name in session level .Provide default catalog name if session expire
Ex :
public string SessionCatalogName
{
get
{
if (HttpContext.Current.Session[APConstants.SessionVariables.CatalogName] != null)
{
return HttpContext.Current.Session[APConstants.SessionVariables.CatalogName].ToString();
}
else
{ return APConstants.ApplicationParameters.GKDefaultCatalogName;
}
}
set
{
HttpContext.Current.Session[ApConstants.SessionVariables.CatalogName] = value;
}
}