Try removing the United Airlines livery. I had the same problem. I had to remove each livery one at a time until I isolated the Untied livery. I couldn’t even start MSFS with that in my community folder.
The only difference was that I downloaded the livery that’s specifically for the developer version of the FBW A32nx.
I hope you’re back up and able to start the game again soon. MSFS 2020 is the best flight sim entertainment I have ever had - maturity bugs and all. It’s just the beginning.