ORA-12516: TNS:listener could not find available handler with matching protocol stack   at OracleInternal.ConnectionPool.PoolManager`3.Get(ConnectionString csWithDiffOrNewPwd, Boolean bGetForApp, OracleConnection connRefForCriteria, String affinityInstanceName, Boolean bForceMatch)
   at OracleInternal.ConnectionPool.OraclePoolManager.Get(ConnectionString csWithNewPassword, Boolean bGetForApp, OracleConnection connRefForCriteria, String affinityInstanceName, Boolean bForceMatch)
   at OracleInternal.ConnectionPool.OracleConnectionDispenser`3.Get(ConnectionString cs, PM conPM, ConnectionString pmCS, SecureString securedPassword, SecureString securedProxyPassword, OracleConnection connRefForCriteria)
   at Oracle.ManagedDataAccess.Client.OracleConnection.Open()
   at UnikConnectivity.Helpers.DatabaseHelper.GetFile(Int32 objectid, String template) in C:\Users\chris\source\repos\chmartit\UnikConnectivity\UnikConnectivity\UnikConnectivity\Helpers\DatabaseHelper.cs:line 136
   at UnikConnectivity.Controllers.ExplorerController.<Show>d__14.MoveNext() in C:\Users\chris\source\repos\chmartit\UnikConnectivity\UnikConnectivity\UnikConnectivity\Controllers\ExplorerController.cs:line 650