Could not load file or assembly (custom dll) - works for console but fails for web project (ASP.NET MVC 5) [duplicate]

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• Could not load file or assembly '***.dll' or one of its dependencies 7 answers

I am building a ASP.NET MVC 5 web app that utilizes SignalR for the communication stack abstraction.

Everything works fine until I add a custom DLL that implements a real-time message bus. Part of the message bus process requires xml files (properly copied to bin deploy folder).

When trying to run the Web project (locally using IISExpress - haven't tried deployment server) I am getting a "Could not load file or assembly 'MSG_BUS.DLL' or one of its dependencies" ... everything works fine when using one of my test harness console projects or before I added the DLL dependency.

Any idea how to troubleshoot or resolve this issue? I suspect it has something to do with the XML files - but have no clue how to resolve it