Hi.
I have installed the ‘Smartir’ integration: ‘https: //github.com/smartHomeHub/SmartIR’. But HA generates an alert:[homeassistant.loader] We found a custom integration smartir which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
This is my version:
Are you serious? 
You are a member here in this very forum for over two years (so I assume, you use HA for at least these two years) and you haven’t noticed this message before? Is this your only custom_component you installed?
Nevermind, the warning (not error) message tells you exactly what is happening. You are using a custom_component that is not tested by the HA core development team. That’s all. Like it says…
And btw. it would be good, if you could take a look at the rules for just a moment (especially the part about formatting), you could find them here:
Maybe it is. The message can be quite alarming first time round. Give the guy a break - you don’t have to reply. Unlike the poor sap on the help desk. That must be the job from hell. 
To harsh? OK, @oldmaker, sorry if this was to harsh, but from your previous posts I could see, that you at least installed one custom_component before, so that mesage shouldn’t be new. 
@Stiltjack Someone should answer, it’s always better to get an answer, even if it is not as charming, as it could be. 
It’s just that this question has been asked and answered numerous times and, as I said, should be nothing new.
That message should be demoted to INFO.
It makes no sense to output of a Warning for using a supported feature…
Thanks everyone for the answers. I’m sorry I was superficial in researching this previously reported problem. I’ll be more careful next time.