Welcome! Looks like you tried to save a device type handler as a smart app or vice versa.
You will get the fastest answer to your question if you ask in the author thread for that particular code.
So go to the following thread (this is a clickable link) check the instructions there, and if that doesn’t clear up any confusion, just ask your question there and someone will be glad to help.
In the future, you might try using the quick browse lists in the community – created wiki to find the author threads quickly.
Looks like you tried to save a device type handler as a smart app or vice versa.