Viber does not detect my contact list on BlueStacks
Viber has not been tested on Bluestacks, as it is not a platform that supports Viber on its  own.

However, in order to have a contact list, Viber syncs to the device on which it is installed. You can try deleting Viber and re-installing to see if it syncs with your contacts. Other than that, there is not much that we can assist with.