Failing genasm.exe due to claimed missing implementation of abstract method

I’m focusing on our Windows Client right now, working out how to handle the loading of lists asynchronously. As a result I’ve just spent a few hours with the following error message:

Error 5 genasm.exe(1) : error There was an error finalizing type . Method ‘ApplyTemplate’ in type ‘xxxxxx’ from assembly ‘xxxx.MobileClient.PocketPC.asmmeta, Version=3.2.2543.1, Culture=neutral, PublicKeyToken=bd562592246cb6f0′ does not have an implementation. MobileClient

To be honest I never did find out why the above error message was displayed. The base-class implements the method the error message says is missing.

public class OrderFiller : BaseListFiller

However; changing the specific class from public to internal fixed the problem

internal class OrderFiller : BaseListFiller