BadImageFormatException. This will occur when runn

Question

I am getting this error while on of my .Net application are trying to make a connection to oracle database.

The error says that This problem will occur when running in 64 bit mode with the 32 bit Oracle client components installed.. But I have made sure many times that the client installed in x64 bit not 32.

Date Time: 6/8/2014 10:57:55 AM: System.InvalidOperationException: Attempt to load Oracle client libraries threw BadImageFormatException.  This problem will occur when running in 64 bit mode with the 32 bit Oracle client components installed. ---> System.BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)
       at System.Data.Common.UnsafeNativeMethods.OCILobCopy2(IntPtr svchp, IntPtr errhp, IntPtr dst_locp, IntPtr src_locp, UInt64 amount, UInt64 dst_offset, UInt64 src_offset)
       at System.Data.OracleClient.OCI.DetermineClientVersion()
       --- End of inner exception stack trace ---
       at System.Data.OracleClient.OCI.DetermineClientVersion()
       at System.Data.OracleClient.OracleInternalConnection.OpenOnLocalTransaction(String userName, String password, String serverName, Boolean integratedSecurity, Boolean unicode, Boolean omitOracleConnectionName)
       at System.Data.OracleClient.OracleInternalConnection..ctor(OracleConnectionString connectionOptions)
       at System.Data.OracleClient.OracleConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
       at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)
       at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)
       at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)
       at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
       at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
       at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
       at System.Data.OracleClient.OracleConnection.Open()
       at CustomizedSetupInstaller.Runscripts.InitializeDBObjects(String connectionString, String dbProvider)

Answer 1

Mine is the console application (it should work for the windows application as well) and I had same problem. To solve it I used PlatformTarget as x64 as my System.Data.OracleClient.dll (64 bit file) is at C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.5. This will explicitly use 64 bit version of Oracle Client. This might help you if your solution works only on 64bit and if you are not using 32 bit dlls like dlls made in VB. I hope it will help you.

Answer 2

I had the same issue on a Windows 10 PC. I copied the project from my old computer to the new one, both 64 bits, and I installed the Oracle Client 64 bit on the new machine. I got the same error message, but after trying many solutions to no effect, what actually worked for me was this: In your Visual Studio (mine is 2017) go to Tools > Options > Projects and Solutions > Web Projects

On that page, check the option that says: Use the 64 bit version of IIS Express for Websites and Projects

Answer 3

As apc mentioned that error occurs "when a 32bit dll calls a 64bit dll or vice versa". The problem is that if you have build using AnyCPU and are running on a 64bit environment then the application will run as 64bit. If rebuilding explicitly for 32 and 64 bit is not an option then you could use a microsoft utility called corflags.exe which comes with the Windows SDK. Basically, you can modify a flag in the exe of the program you are executing to tell it to run as 32bit even if the environment is 64bit.

See here for information on using it

Answer 4

I got this issue for a console Application. In my case i just changed the Platform Target to "Any CPU" which you can see when you right click your solution and click on properties , you will find a Tab "Build" click on it you will see "Platform target:" change it to "Any CPU", which will solve your issue

Answer 5

Please download the correct version of Oracle Client like Oracle Client 11.2 32-Bit; which resolved the problem for me.

Answer 6

Just build your code in x86 mode not in AnyCpu.