Cannot view app on browser

I am getting an error 404 Not Found: Requested route ('') does not exist i am not getting why?
1 answers

I would think that the app has never been deployed to the sandbox or has been deleted.

Another option is that you used the default cloud project and ended up with a Mendix 5.x version and the sandboxes only allow to run Mx6+ versions. If this is the case upgrade your project to a Mx 6 version. Delete the old project, export the project from the modeler and import it into a Mx 6 version modeler and make sure to use the team server when asked.