Wow, I sure wasted a lot of time on this just to find out that it's the name of the file that BalenaEtcher doesn't like. Good grief. I proceeded just fine with BalenaEtcher after changing the ".iso" suffix to ".dd". And now I wonder if I could have just used dd to copy the file to the flash drive. I don't know what BalenaEtcher or Rufus apps do to make an iso file bootable. I know that I've used dd with success before. I believe it depends on how the iso file is written, but I don't know the det...
Copy and paste the entire license key. Before you even start that, make sure you've got good connectivity to the internet.