Could not load file or assembly

Question

I'm working on a system to use a SqlServerCe with NHibernate. From my driver program, if I add the System.Data.SqlServerCe assembly as a reference, I can create and run queries against a database just fine. When trying to use NHibernate, though, I get the following exception:

A first chance exception of type 'System.IO.FileNotFoundException' occurred in mscorlib.dll Additional information: Could not load file or assembly 'System.Data.SqlServerCe' or one of its dependencies. The system cannot find the file specified.

I've traced the exception to a call to Assembly.Load("System.Data.SqlServerCe"), which seems like it should work. The System.Data.SqlServerCe assembly is in the GAC (I've also tried to add it as a local reference with CopyLocal=true, to no avail), and I can use its members fine, so why can't I explicitly load it? When I open the assembly in Reflector, it has trouble loading the System.Transactions reference (I've also tried adding it as a local reference, again to no avail), so loading that assembly might be the problem, rather than the System.Data.SqlServerCe assembly.

Is this a common problem? System misconfiguration, maybe?

Answer 1

Looks like you never heard about Fusion:

http://www.hanselman.com/blog/BackToBasicsUsingFusionLogViewerToDebugObscureLoaderErrors.aspx

Answer 2

Apparently this can be solved by adding a <qualifyAssembly> element to the app.config file. Adding the following has my app running smoothly:

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <qualifyAssembly partialName="System.Data.SqlServerCe" fullName="System.Data.SqlServerCe, Version=3.5.1.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />
    </assemblyBinding>
</runtime>

Thanks!