unable to find characteristics of the peripheral in IOS application

[cis-apoorv]

Hi,
I'm trying to connect raspberry pi to IOS application via Bluetooth. Using your echo example code I was able to create an advertising service successfully but, when I tried to send a message after connecting to the IOS application I'm not able to get the characteristics at my end due to which IOS application get crashed.
I tried debugging and found that peripheral.services.first.characteristics is returning 'nil', which means that the advertising service does not have characteristics.

Please let me know what I'm doing wrong.
Here's the link to the example code I'm using:
https://github.com/Adam-Langley/pybleno/blob/master/examples/echo/main.py
https://github.com/Adam-Langley/pybleno/blob/master/examples/echo/EchoCharacteristic.py

[Adam-Langley]

Hi @cis-apoorv, you'll need to submit some environmental information and stack traces for me to be able to offer any suggestions.
Thanks,