Could not load file or assembly \'NCrawler.GeckoProcessor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null\' or one of its dependencies.
This error usually means that the assembly was not found. Try verifying that the file exists in the directory where your application is running.
If you still can't figure out which file fails loading, try using a tool such as Fusion Log Viewer (run fuslogvw.exe from the Visual Studio command prompt), to determine which files the CLR was trying to load and from where, so that you can see exactly what failed.