BizTalk Server 2016: Could not load file or assembly “Oracle.DataAccess, Version=4.121.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342” or one of its dependencies. The system cannot find the file specified.

It is not the first time, nor will it be the last, that I have encountered similar problems like this one, or the same problem in earlier versions. We call it DLL hell (or nightmare), but I think all BizTalk Administrators are familiar with it and have been vaccinated against the problem. Some months ago, while trying to communicate with an Oracle database within Visual Studio in a brand-new BizTalk Server 2016 Developer environment to generate the proper Schemas, we faced with the following Oracle.DataAccess problem:

Error saving properties.
(System.ArgumentException) Invalid binding.
(System.IO.FileNotFoundException) Could not load file or assembly ‘Oracle.DataAccess, Version=4.121.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342’ or one of its dependencies. The system cannot find the file specified.

Cause

When installing the Oracle WCF Adapter for BizTalk Server 2016, there is a design-time requirement to use Oracle.DataAccess Version 4.121.1.0.

BizTalk Server 2016 requires a specific Oracle.DataAccess version. However, we verified to the GAC that the DLL present in our environment had a different version.

Trying to find the correct ODP.NET 11.2.0.1.2 version under Oracle website can be a challenge

Note: depending on the BizTalk Server version that you are using, this the required Oracle.DataAccess version may change.

Solution

Trying to find the correct ODP.NET 11.2.0.1.2 version under the Oracle website can be a challenge, so one of the easiest and fastest ways to solve this problem is using Assembly Binding Redirection in the machine configuration file (Machine.config):

• 32-bit: c:\Windows\Microsoft.NET\Framework\[version]\config\machine.config
• 64-bit: c:\Windows\Microsoft.NET\Framework64\[version]\config\machine.config

Note: You should apply this in both 32 and 64-bit machine configuration files.

By using the <assemblyBinding> Element for <runtime>, which will contain all the information about assembly version redirection and the locations of assemblies.

In this case, you should apply the following configurations:

<runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
    <dependentAssembly>
      <assemblyIdentity name="Oracle.DataAccess"
         publicKeyToken="89b483f429c47342" />
      <bindingRedirect oldVersion="4.121.1.0" newVersion="x.xxx.x.x" />
    </dependentAssembly>
  </assemblyBinding>
</runtime>

By doing this, BizTalk Server will look to the Oracle.DataAccess version which not exists in your environment, it will be redirected to the existing DLL version.

For example, in our case, we used:

<!--<runtime />-->
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Oracle.DataAccess" publicKeyToken="89b483f429c47342" />
        <bindingRedirect oldVersion="4.121.1.0" newVersion="4.121.2.0" />
      </dependentAssembly>
   </assemblyBinding>
</runtime>

Just to be on the safe side, you should add this configuration to both 32-bit and 64-bit .NET Framework 2.0 and 4.0 machine configuration files.

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Author: Sandro Pereira

Sandro Pereira lives in Portugal and works as a consultant at DevScope. In the past years, he has been working on implementing Integration scenarios both on-premises and cloud for various clients, each with different scenarios from a technical point of view, size, and criticality, using Microsoft Azure, Microsoft BizTalk Server and different technologies like AS2, EDI, RosettaNet, SAP, TIBCO etc. He is a regular blogger, international speaker, and technical reviewer of several BizTalk books all focused on Integration. He is also the author of the book “BizTalk Mapping Patterns & Best Practices”. He has been awarded MVP since 2011 for his contributions to the integration community. View all posts by Sandro Pereira