The provider is not compatible with the version of Oracle client

I've been looking into this problem further, and you simply need to grab all the appropriate DLL's from the same downloaded version of ODP.Net and put them in the same folder as your Exe file, because ODP.Net is fussy about not mixing version numbers.

I've explained how to do this here: http://splinter.com.au/using-the-new-odpnet-to-access-oracle-from-cHere's the gist of it though:

• Download ODP.Net
• Unzip the file
• Unzip all the JAR's in it
• Grab these dll's that were just unzipped:
  • oci.dll (renamed from 'oci.dll.dbl')
  • Oracle.DataAccess.dll
  • oraociicus11.dll
  • OraOps11w.dll
  • orannzsbb11.dll
  • oraocci11.dll
  • ociw32.dll (renamed from 'ociw32.dll.dbl')
• Put all the DLLs in the same folder as your C# Executable

You should "ignore" all the x86/x64 talk here for starters and instead try the ODP.NET Managed Driver (if you are using .Net v4+):

https://www.nuget.org/packages/Oracle.ManagedDataAccess/

https://www.nuget.org/packages/Oracle.ManagedDataAccess.EntityFramework/

Oracle ODP.net Managed vs Unmanaged Driver

Avoid all the "unmanaged" what DLL what architecture issues! :D (about time Oracle).

The NuGet package (also works for 11g):

The old / manual method:

For info on how to convert to using the managed libraries:

• First, here is a great code comparison of managed vs unmanaged: http://docs.oracle.com/cd/E51173_01/win.122/e17732/intro005.htm#ODPNT148
• Ensure you have downloaded the ODP.NET, Managed Driver Xcopy version only
• From the downloaded zip file, copy and paste into your project directory:
  • Oracle.ManagedDataAccessDTC.dll
  • Oracle.ManagedDataAccess.dll
• Add a reference to Oracle.ManagedDataAccess.dll
• Ensure your exe is released (added to Application Folder in VS2010) with both dlls

I only installed the Oracle Data Provider for .NET 2.0 (11.1.0.6.20) and I did not install the Oracle Instant Client (11.1.0.6.0).

I just installed it and the error disappeared!