Hi Ajit,
It’s a bug, I have the same in Mx 9.8.0, you should create a ticket for it.
In the mean time, the barcode is only used to scan the ip address and port of your PC. If you know these you can still run your app and show it on your mobile device.
You’ll need the ip address of your machine, which you can retrieve via the windows cmd: ipconfig (from CLI). If you didn’t change the port, it’ll be 8080. So in your MiN app you can use it like: <ip address>:8080 and type it in the textbox on the start screen.
Alternatively, you can create an starter mobile app in Mx 9.6 and scan that code, because there “View your device” still works. It will give you the ip address and port as well in your MiN app. Then switch to your 9.7 /9.8 Mx version and run that app.
HTH.