Do you realise what you say ?
I surely do, you probably don't.
I always run the offline installer, as a last step, after any version update. It was the case with this 3.5.8 !
First, you didn't say that, so how I could have possibly know you "always" do that ?
followed by the offline installer and I got again an infinite loading (see the picture), but this time, I was able to kill & then, restart couatl without the dead loop on the error "problem raised by addon <unknown>" and finally, the menu screen loaded, after multiple loading info message poped in the menu window.
Let's not confuse two completely different things:
- The ERROR in your previous log will surely gone if you perform an update. If your local cloudflare node is normally updated, it will be gone after a normal update, but if it's not, the Offline installer will surely fix it because, again, that error has been fixed several days ago, and you can be sure the Offline installer contains the fix. Obviously, you must download it again, it's offline, so you can't expect one you downloaded last week would somehow update itself with the fix so, clearly, when I say "Use the Offline installer", always means "Download again the Offline installer now, and install it"
- The infinite loop sometimes happens in MSFS 2020, but it normally goes away if you restart the Couatl engine as explained at Page 97 of the manual and, as that page suggest, don't keep restarting over and over, because after an update (online or offline), it must regenerate the models cache once, so the FIRST start after an update will take longer, and it's normal, and you shouldn't restart before it's done, otherwise you'll abort the model cache creation and you'll force it to restart it from scratch, over and over.
So, just restart and let it load. Normally 15-20 seconds before trying another restart it's ok, but after an update, it might take up to a minute.