On logs you will see the plugin asking information to add the device, can be usefull to see if there is not an error.
And BTW the front end can’t work on your side, not only the clean api fonction, the discovery is disabled, it’s something normal or a network issue ?
Okay, i disabled and re-activated discovery again, now i can discover conbee again… it does output some data like ip, mac, etc…
Another thing is happened:
Yesterday i updated the firmware of my conbee II and gui to 2.17.1, but when i switch some switches to off it goes on again after a minute or so, even after reboot, i keep pressing OFF, but it keeps turning ON, weird thing!
Downgraded back to 2.16.01 and firmware to 26780700 fixed it again and switch stays off…
For the discovery issue, it’s an easy way for me, I will try to make a “off line” mode this week.
But you have succed to clean the api key lists now ?
I don’t think your issue is from the firmware, more the deconz version. But need more explanation.
What is the model id / manufacture name of faulty devices ?
When you say “i keep pressing OFF” you mean physically ? it’s wired devices ?
Okay 
no, i’m still not succeed in cleaning the api keys, i don’t get it why it does not work.
I already made a new key, also removed the plugin and added it again, also update to latest github version, etc, but it does not want me to do 
It s more a plugin issue, so pls continu in PM