Context
I have two application in place, one is my main enterprise application and in other I have hangfire (hangfire server, client and dashboard) host
I've stumbled upon the same issue a few days ago and decided it's worth adding it here.
Solution: added a reference to 'MyApp.Hangfire' in the dashboard web app.
Context was very similar or identical to yours:
-Hangfire server was running as a Windows service;
-Hangfire dashboard running on top of a ASP.NET MVC 5 app;
-jobs were actually running but dashboard kept displaying a FileNotFoundException;
Same problem was reported and solved in the same way by @reggieboyYEAH.
Details here: https://github.com/HangfireIO/Hangfire/issues/558