Oracle – Could not load file or assembly ‘Oracle.DataAccess’ 64 bit ODP.NET

asp.netodp.netoracle

I am using ODP.NET in my asp.net project in order for the application to talk to oracle 11 g Express on Windows 2008 server (32 bit). While on development machine I had Windows 7 (32 bit). I installed Windows 8 (64 bit) on the development machine and tried to run the application from visual studio 2012, It gave the error 'Could not load file or assembly 'Oracle.DataAccess''. After a little search I realized that I have to install ODP.NET (64 bit) in order to use it on 64-bit machine, so I uninstalled the 32 bit version and installed 64-bit ODP.NET. Removed the reference to old Oracle.DataAccess but still facing the same issue. Am I missing something??

Best Answer

I had the same issue and after some trial and error I found that the issue is with 32 bit vs 64 bit platform.

When we deploy 32 Bit Oracle.DataAccess.dll along with web application over 64 bit environment and ODP.net installed over server this error will occur.
One solution is to delete the Oracle.DataAccess.dll from bin folder and correct reference will be auto resolved.
Second solution is to set the reference property CopyToLocal=false for Oracle.DataAccess.dll and hence it wont go with build when you deploy on IIS and error will not occur.
Third solution which I will prefer is to enable 32 bit applications for your application pool and you wont face this issue again irrespective of whether Oracle.DataAccess.dll is present in bin folder or not.

Hope this helps..

Related Solutions

Windows – How to Make ODP.NET 4.0 (64 bit) working on 64 bit machine Windows 7

The best possibility to handle this is to use the x86 version locally with Visual Studio and x64 version on the server with IIS. To do this you have to download both versions - copy one in folder lib\x86 and the other in lib\x64 After this you have to modify the project file(s) - visual studio supports conditional references. Add following section to your project file:

<PropertyGroup>
     <ReferencesPath Condition=" '$(Platform)' == 'x86' ">..\Lib\x86</ReferencesPath>
     <ReferencesPath Condition=" '$(Platform)' == 'x64' ">..\Lib\x64</ReferencesPath>
</PropertyGroup>

After this reference the odp.net assmebly like this:

<Reference ... processorArchitecture=$(Platform)">
   <SpecificVersion>False</SpecificVersion>
   <HintPath>$(ReferencesPath)\Oracle.DataAccess.dll</HintPath>
   <Private>True</Private>
</Reference>

This way when you can build locally as x86 and on the server x64 and always the correct version of Oracle.DataAccess.dll will be referenced.

Alternatively if you only want to use the x64 version than you have to stick to IIS even you work locally OR you could try to run the open source version of Cassini in x64 mode (http://cassinidev.codeplex.com).

For me the best possibility is to reference both versions as described above - this has been working fine for everyone on my team for a while now.

Vb.net – Could not load file or assembly ‘Oracle.DataAccess’ – Markup View

Expressly set the "Platform target" to "x86" or "x64" in the project properties --> Build tab. enter image description here

Do NOT set it to "Any CPU." This is one of many common conditions which causes this driver of typical Oracle software quality to have a nervous breakdown.

Best Answer

Related Solutions

Windows – How to Make ODP.NET 4.0 (64 bit) working on 64 bit machine Windows 7

Vb.net – Could not load file or assembly ‘Oracle.DataAccess’ – Markup View

Related Topic