server transfer error Invalid Path Character

[lexus]

hola
tengo este codigo

Código HTML:

dim sqlf123,rsf123
sqlf123 = "SELECT id_usuario FROM mascotas where alias = '"&alias&"' limit 0,1"
Set rsf123 = oConn.Execute(sqlf123)
if not rsf123.eof then
 
url = "../perfil/perfil.asp?mascota="&rsf123("id_usuario")
server.Transfer(url)
else
response.redirect "../principal/inicio.asp"
end if
rsf123.close
set rsf123= nothing
 

no me esta haciendo el server.transfer me sale este error.

Invalid Path Character
/errores/pagina.asp, line 16 An invalid character was specified in the Path parameter for the MapPath method.