Exception ORA-12537: Network Session: End of file, Oracle.ManagedDataAccess

Question

My environment:
> Oracle 11g expression edition in Win7 ("DevDB")
> Oracle 11g in non-Windows platform ("ProDB")
> Oracle.ManagedDataAccess.dll (file version is 4.121.1.0, product version is 4.121.1.20131211)
> Instant client sqlplus
If I use sqlplus to connect "DevDB" and "ProDB" with following command, both DBs can be connected successfully.
> sqlplus someUser@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xxx.xxx)(PORT=1521))(CONNECT_DATA=(SID=DBSID)))
If I use following codes with Oracle.ManagedDataAccess.dll to connect DBs.
string connectionString = "User Id=someUser;Password=somePwd;Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xxx.xxx)(PORT=1521))(CONNECT_DATA=(SID=DBSID)))";
OracleConnection con = new OracleConnection(connectionString);
try{
  con.Open();
} catch (Exception e) {
  Console.WriteLine(e.Message);
  Console.WriteLine(e.StackTrace);
} finally {
  if (con != null)
  con.Dispose();
It can connect to "DevDB" successfully. However, when I try to connect "ProDB", it throws following exception.
ORA-12537: Network Session: End of file
   at OracleInternal.ConnectionPool.PoolManager`3.CreateNewPR(Int32 reqCount, Boolean bForPoolPopulation, ConnectionString csWithDiffOrNewPwd, String instanceName)
   at OracleInternal.ConnectionPool.PoolManager`3.Get(ConnectionString csWithDiffOrNewPwd, Boolean bGetForApp, String affinityInstanceName, Boolean bForceMatch)
   at OracleInternal.ConnectionPool.OraclePoolManager.Get(ConnectionString csWithNewPassword, Boolean bGetForApp, String affinityInstanceName, Boolean bForceMatch)
   at OracleInternal.ConnectionPool.OracleConnectionDispenser`3.Get(ConnectionString cs, PM conPM, ConnectionString pmCS, SecureString securedPassword, SecureString securedProxyPassword)
   at Oracle.ManagedDataAccess.Client.OracleConnection.Open()
Any tips to fix this problem?
Thanks

Answer 1

I added following settings in app.config file
  <configSections>
    <section name="oracle.manageddataaccess.client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess" />
  </configSections>
  <oracle.manageddataaccess.client>
    <version number="*">
      <settings>
        <setting name="SQLNET.AUTHENTICATION_SERVICES" value="all"/>
        <setting name="NAMES.DIRECTORY_PATH" value="ezconnect"/>
      </settings>
    </version>
  </oracle.manageddataaccess.client>
Still failed, sometimes it throws "ORA-12537: Network Session: End of file", sometimes throws "ORA-03135: Connection lost contact".
As ORA-12537 after change to Oracle.ManagedDataAcess.dll mentioned, it works without any problem with the unmanaged library.Please advice, thx.