I struggled with this for hours, for me it wasn't any of the above.

In development everything worked fine, but in production i got the error.

Fix: double check the capitalization of the class. Seems homestead cares less about capitalization than forge.

Hope this helps anyone!

Hi, I had the same error, the error generated for my as I was merging an outdated branch in my current development branch, because of this the config/app.php got the service providers and the aliases duplicated, I just fixed this and the problem is gone.