If a device that you rent from the Service Provider is blocked or unblocked by the Service Provider, you will receive a notification about that.
If a rent device is blocked by the Service Provider, you are not allowed to operate the device via the Mobile Client. In this case, you can contact the Service Provider and ask her/him to unblock the device if required.
For such a notification, you can view the Service Provider who block/unblock the device and the site where the device is added.