Unable to connect to Oracle database

hi Team,

I am struggling to connect to Oracle database for a few days, the test application works perfectly fine on my machine, but when the other users try to run the same application, they are getting below errors:

See the end of this message for details on invoking 
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.TypeInitializationException: The type initializer for 'Oracle.DataAccess.Client.OracleConnection' threw an exception. ---> System.BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)
   at Oracle.DataAccess.Client.OpsInit.CheckVersionCompatibility(String version)
   at Oracle.DataAccess.Client.OracleInit.Initialize()
   at Oracle.DataAccess.Client.OracleConnection..cctor()
   --- End of inner exception stack trace ---
   at Oracle.DataAccess.Client.OracleConnection..ctor()
   at CredentialVerifier.Form1.btnConnect_Click(Object sender, EventArgs e) in C:\Projects\CredentialVerifier\CredentialVerifier\Form1.cs:line 35
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3324.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll
----------------------------------------
CredentialVerifier
    Assembly Version: 1.0.0.0
    Win32 Version: 1.0.0.0
    CodeBase: file://NAS drive/Credential_Verifier/CredentialVerifier.exe
----------------------------------------
System.Windows.Forms
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3324.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3353.0 built by: NET472REL1LAST_B
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3221.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Configuration
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3324.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Core
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3324.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Xml
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3221.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
Accessibility
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.2558.0 built by: NET471REL1
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_MSIL/Accessibility/v4.0_4.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
----------------------------------------
Sybase.Data.AseClient
    Assembly Version: 1.155.10000.0
    Win32 Version: 1.155.10000.0
    CodeBase: file://NAS drive//Credential_Verifier/bin/DLLs/Sybase.Data.AseClient.DLL
----------------------------------------
System.Data
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3260.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_32/System.Data/v4.0_4.0.0.0__b77a5c561934e089/System.Data.dll
----------------------------------------
Oracle.DataAccess
    Assembly Version: 4.121.2.0
    Win32 Version: 4.121.2.0
    CodeBase: file://NAS drive/Credential_Verifier/bin/DLLs/Oracle.DataAccess.DLL
----------------------------------------
System.Transactions
    Assembly Version: 4.0.0.0
    Win32 Version: 4.7.3221.0 built by: NET472REL1LAST_C
    CodeBase: file:///C:/windows/Microsoft.Net/assembly/GAC_32/System.Transactions/v4.0_4.0.0.0__b77a5c561934e089/System.Transactions.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

below are the code used to connect to Oracle database:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//using System.Data.OracleClient;
using Oracle.DataAccess.Client;
using Oracle.DataAccess.Types;
using Sybase.Data.AseClient;
using System.Windows.Forms;

string strErrorMsg = String.Empty;
string sybaseConError = string.Empty;
string oracleConError = string.Empty;

OracleConnection oracleConn = new OracleConnection();
string connString = "Data Source= oracle db server;User Id=" + txtUserName.Text + ";Password=" + txtPassword.Text + ";";
oracleConn.ConnectionString = connString;
oracleConn.Open();
connected = true;
MessageBox.Show("Connected successfully.");

I have reference teh Oracle.DataAccess dll file to a NAS drive:     CodeBase: file://NAS drive/Credential_Verifier/bin/DLLs/Oracle.DataAccess.DLL to make sure that users are using the designated dll file, but users are still getting above errors, what could be wrong.....