I "discovered" that if power state of lightbulb is 0 you can not read or write brightness level.
To get over this issue I read power state and if it was 0 I changed it to 1 first then change brightness level.
When reading brightness level just to show on screen if power state was 0
I just made it 0 in my indication system.
It is a shame that I could not read this in documentation.
Topic:
App & System Services
SubTopic:
General
Tags: