Stopping/Starting FTP site in IIS via command prompt error

Question

I use the batch file command:

appcmd site stop "name"

but when I use it on my FTP site in the IIS, it returns an error:

< hresult:800710d8, message:Command execution failed. The object identifier does not represent a valid object. >

my batch file works fine for other sites, just this one ftp site is returning that error.