Hi,
I tried clicking the “Add an App” link inside the App tab.
The “Accept” button is responsive from UI perspective but there’s no logic connected to it, meaning that the button looks like it’s doing something but in fact nothing happens.
You should check after the power cycle of My Cloud device, disconnect all the cables and power adapters, reconnect them and try to add an app again from the dashboard of My Cloud DL4100.
I think a file selection dialogue should appear allowing you to select the .bin file on the computer. I’m not sure why that had not happened. Sorry I can’t be of much more help. This particular issue I’ve not encountered, yet. It’s difficult to determine the cause when I can’t replicate the symptoms.