MEF: “Unable to load one or more of the requested types. Retrieve the LoaderExceptions for more information”

Question

Scenario: I am using Managed Extensibility Framework to load plugins (exports) at runtime based on an interface contract defined in a separate dll. In my Visual Studio solut

Answer 1

I have also run into a similar problem.

If you are sure that you want to ignore such "bad" assemblies, then the solution is to call AssemblyCatalog.Parts.ToArray() right after creating each assembly catalog. This will trigger the ReflectionTypeLoadException which you mention. You then have a chance to catch the exception and ignore the bad assembly.

When you have created AssemblyCatalog objects for all the "good" assemblies, you can aggregate them in an AggregateCatalog and pass that to the CompositionContainer constructor.