title: Deploying web server that uses Oracle.DataAccess results in various assembly errors
body: <p>My development machine is Vista x64.</p>
  
  <p>I am using WCF web services to build web services interfacing to an oracle 10g database.</p>
  
  <p>When development started, I could not use VS2008's built-in WCF test tool [WCFTestClient] that launches when you press F5 [Go], on the 32-bit Oracle.DataAccess.dll, because I get System.BadImageFormatException on the Oracle object. So in my development environment I switched to the ODP.NET 64 bit version for my referenced assembly, and that works great.</p>
  
  <p>I can deploy to my local IIS [7], but only if I use the 32bit Oracle.DataAccess.dll.</p>
  
  <p>I am trying to deploy to a Win2003 [IIS 6] that has .NET 3.5 sp1 installed, and Oracle 10g database installed. Other web applications on this server successfully use oracle connections.</p>
  
  <p>If I remove all references to Oracle.DataAccess from the web.config file , and make sure there is no Oracle.DataAccess.dll in my bin/ folder, I can bring up the default service metadata page[s], but calling the service via a SOAP client results in an error:</p>
  
  <p>"Could not load file or assembly 'Oracle.DataAccess, Version=10.2.0.100, Culture=neutral, PublicKeyToken=89b483f429c47342' or one of its dependencies. The system cannot find the file specified."</p>
  
  <p>However, if I put a copy of Oracle.DataAccess.dll in my bin/ folder, I get:</p>
  
  <p>"Could not load file or assembly 'Oracle.DataAccess' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)" </p>
  
  <p>when trying to load the .svc page in a web browser.</p>
  
  <p>If I add an assembly reference to my web.config, I get a configuration error: "Could  not load file or assembly xxx"</p>
  
  <p>I guess I'm looking for help understanding the assembly cache, and someone who has experience with ODP.net who can help me navigate this treacherous territory and get this service successfully deployed.</p>