Erro TNSNAMES.ORA - 12154

<connectionStrings>

<add name="connectionString" connectionString="Data Source=XE;User ID=HR;Password=admin" providerName="System.Data.OracleClient"/>
</connectionStrings>

XE =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = Roberto-PC)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = XE)
    )
  )
EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )
ORACLR_CONNECTION_DATA = 
  (DESCRIPTION = 
    (ADDRESS_LIST = 
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE)) 
    ) 
    (CONNECT_DATA = 
      (SID = CLRExtProc) 
      (PRESENTATION = RO) 
    ) 
  )