Devart Error:"Unable to load C:\oracle\product\11.2.0\client_1\oci.dll" while connecting oracle data base

Problem
After creating a WCF Data Service using Devart data driver , it failed to connect to data base when deployed on production/test servers but works perfectly fine with localhost

Error Message and Stack Trace
- <error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
  <code /> 
  <message xml:lang="en-US">An error occurred while processing this request.</message>


- <innererror>
  <message>Exception has been thrown by the target of an invocation.</message>
  <type>System.Reflection.TargetInvocationException</type>
  <stacktrace>at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters) at System.Data.Services.RequestQueryProcessor.GenerateQueryResult() at System.Data.Services.RequestQueryProcessor.ProcessQuery() at System.Data.Services.RequestQueryProcessor.ProcessQuery(IDataService service, RequestDescription description) at System.Data.Services.RequestUriProcessor.ProcessRequestUri(Uri absoluteRequestUri, IDataService service) at System.Data.Services.DataService`1.HandleRequest()</stacktrace>
- <internalexception>
  <message>The underlying provider failed on Open.</message>
  <type>System.Data.EntityException</type>
  <stacktrace>at System.Data.EntityClient.EntityConnection.OpenStoreConnectionIf(Boolean openCondition, DbConnection storeConnectionToOpen, DbConnection originalConnection, String exceptionCode, String attemptedOperation, Boolean& closeStoreConnectionOnFailure) at System.Data.EntityClient.EntityConnection.Open() at System.Data.Objects.ObjectContext.EnsureConnection() at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source) at System.Linq.Queryable.LongCount[TSource](IQueryable`1 source)</stacktrace>
- <internalexception>
  <message>Unable to load C:\oracle\product\11.2.0\client_1\oci.dll. Please check that you use 64x version of Oracle client with 64x application.</message>
  <type>Devart.Data.Oracle.OracleProviderException</type>
  <stacktrace>at Devart.Data.Oracle.aw..ctor(Boolean A_0, Boolean A_1, OracleHome A_2) at Devart.Data.Oracle.aw.a(Boolean A_0, Boolean A_1, OracleHome A_2, Boolean A_3) at Devart.Data.Oracle.OracleInternalConnection..ctor(z connectionOptions, OracleInternalConnection proxyConnection) at Devart.Data.Oracle.cs.a(i A_0, Object A_1, DbConnectionBase A_2) at Devart.Common.DbConnectionFactory.a(DbConnectionPool A_0, i A_1, DbConnectionBase A_2) at Devart.Common.DbConnectionPool.a(DbConnectionBase A_0) at Devart.Common.DbConnectionPool.GetObject(DbConnectionBase owningConnection) at Devart.Common.DbConnectionFactory.a(DbConnectionBase A_0) at Devart.Common.DbConnectionClosed.Open(DbConnectionBase outerConnection) at Devart.Common.DbConnectionBase.Open() at Devart.Data.Oracle.OracleConnection.Open() at System.Data.EntityClient.EntityConnection.OpenStoreConnectionIf(Boolean openCondition, DbConnection storeConnectionToOpen, DbConnection originalConnection, String exceptionCode, String attemptedOperation, Boolean& closeStoreConnectionOnFailure)</stacktrace>
- <internalexception>
  <message>An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)</message>
  <type>System.BadImageFormatException</type>
  <stacktrace>at OciDynamicType.nativeOCIEnvCreate(IntPtr& , Int32 , IntPtr , IntPtr , IntPtr , IntPtr , UInt32 , UInt32 ) at Devart.Data.Oracle.aw..ctor(Boolean A_0, Boolean A_1, OracleHome A_2)</stacktrace>
  </internalexception>
  </internalexception>
  </internalexception>
  </innererror>
  </error>

Root Cause

There could be three possible issues in case of such errors

1. Conflict in binary version conflict in between Devart and database, In our case it was negative
2. Devart is not able to locate correct oracle home.In our case it was negative
3. Local host is using TNS bases connection string and the same TNS file is not available on server.This is most likely root cause 

Solution

• For point 1-2 solution is self explanatory
• For 3 instead of TNS based connection string use full connection string with actual server name and port information.

Example
            Connection String Before
                         [TODO]

             Connection String After
                       [TODO]