In Visual Studio 2012 Update 1, we removed several internal limitations that caused Fakes silently skip generation of stubs and shims. LogWriter happened to be one of the classes that VS2012 RTM silently skipped. Unfortunately, improvements in Update 1 expose some other limitations in Fakes, which in this case is its inability to distinguish between generic and non-generic overloads of the GetFilter method of the LogWriter class.
As a workaround, remove this type from Fakes configuration. Here is a .Fakes file that accomplishes that.
<Fakes xmlns="http://schemas.microsoft.com/fakes/2011/">
<Assembly Name="Microsoft.Practices.EnterpriseLibrary.Logging" Version="5.0.505.0"/>
<StubGeneration>
<Remove FullName="Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter!"/>
</StubGeneration>
</Fakes>
As a general practice, it is better to modify the default .Fakes files and specify only the stub and shim types you need in your project. This significantly improves build time and helps avoid Fakes limitations that don't apply to your testing needs.
<Fakes xmlns="http://schemas.microsoft.com/fakes/2011/" Diagnostic="true">
<Assembly Name="Microsoft.Practices.EnterpriseLibrary.Logging" Version="5.0.505.0"/>
<StubGeneration>
<Clear/>
<Add FullName="Namespace.TypeName!"/>
</StubGeneration>
<ShimGeneration>
<Clear/>
<Add FullName="Namespace.TypeName!"/>
</ShimGeneration>
</Fakes>