Question

I have a v4.0 assembly that is both in the GAC (4.0 location) for runtime use and in a location on disk for designtime use. I have the designtime DLL’s location set in the registry so that I can add it via Add Reference in Visual Studio.

I also have a service that is using this DLL. I added it via Add Reference and can compile without issue while referencing its classes. However, when I run my service, it doesn’t pull the DLL from the GAC, and I get an error that the service can’t find a class in the GACked DLL. I can change “copy local” to true and it will work just fine, but that defeats the purpose of having the DLL in the GAC.

Any suggestions on how to troubleshoot?

---

I can add as reference to a new console app and access the object. Not sure what the issue is with the service.

---

It may not be finding the type.. but I can reference the type from the console app (using the GACked assembly), so I’m not sure why it can’t find it when running the service.

Answer 1

You will need to add the assembly under the system.web tag in the machine.config

<system.web>
    <compilation>
        <assemblies>
            <add assembly="YOUR_DLL_NAME, Version=1.1.0.0, Culture=neutral, PublicKeyToken=YOUR_KEY_TOKEN" />  
        </assemblies>
    </compilation>
</system.web>

Depending on your setup, the configuration file can be found:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config
or
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.config