FYI this is an issue with chromecast audios - “app not found” I think means nothing is connected to it, so there is no app running. It works if I’m sending music to the device.
I know it’s quite old, but did you resolve the issue? I have the same error message No application is running in ChromeCast when I try to start the streaming to my chromecast audio.
I’ve connected to the chromecast with the current openhab2 binding. Setting volume and using the setUri function works fine. Just when I want to start the streaming it get this error message. Any Ideas what how to solve this?