The "Libreelec configuration" addon doesn't launch on Raspberry Pi3.
On updated system or a new installation.
Because of this, the "Libreelec" button in the system settings doesn't work.
Hi, Just think a bit about this. It's many people using LE with RPi3, me too, and if should be a bug like this in LE, here would be a lot of complains. Another things: what LE version do you use? Where is the log to be able to see what's wrong with your device? Did you tried with a fresh install on a spare SDcard?
For logs read wiki.libreelec.tv/support/log-files.