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
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.