Thanks! Yeah it was a bit stupid of me to install the RC on my main Homey: I don’t have a test Homey for nothing, do I 
But because it ran fine with the RC update I didn’t see much risk.
Nothing I know gets it into recovery or online, it most probably needs a reflash (here or at your hometown).
Let’s hope that brings it to life again! 
I just restored the main Homey backup to the HFKATH (Homey formerly known as test Homey), I’m back in business.
Because “Experimental updates” was still enabled, v12.9.0-rc.4 was installed and it runs fine.
Only all apps lacked, I had to install all apps myself 
